Small, flat, and wily, cockroaches are expert opportunists that – without certain simple precautions – can invade our spaces quickly. But where do roaches come from and how are they getting in?

Let’s shrink down to their size for a minute, see how they’re sneaking in, and learn how to stop them at the door.

The Two Types of Invaders: Roaches that Come from Outside, and Roaches that Come from Other People’s Stuff.

To get a handle on this vexing little origin story (that dates back more than 320 million years), it helps to understand that roaches come in two distinct varieties: Outdoor roaches, and indoor roaches.

The two types of roaches not only have different habitats, lifestyles, and adaptations, but use different modes of entry to invade and inhabit your home or business.

Where Outdoor Roaches Come From

The Main Invaders: American cockroach, Oriental cockroach, Wood cockroach, and increasingly the Turkestan cockroach.

Outdoor roaches live everywhere outdoors that have the conditions to support them: food, shelter, warmth, and generally, darkness and lots and lots of water. That means otherwise healthy habitats like mulch, hollow tree trunks, log piles, and decaying ground cover… but also unhealthy ones like garbage heaps and sewers.

When they decide to leave those outdoor spaces, there are a number of ways they get inside:

The ground around your house

These bugs are made for walkin’. The life of a cockroach is a life spent crawling through dirt, grass and mulch.

Even if your house is surrounded by urban concrete, roaches have no problems living in alleyways and around dumpsters. These species of roaches hide and hang out on the ground right around your home. It’s almost inevitable that they’ll find a way in.

How they get in: A roach’s shape and size are perfect for squeezing through tiny holes and slim crevices in the foundation or walls of a house.

You might forget that, besides the cracks from normal wear and tear, there are holes in the walls of your home that were put there on purpose. Important piping and wiring has to pass through somehow! Dryer vents and bathroom vents could let cockroaches and other critters inside if they’re not covered.

Pest control tip: You can fill cracks and crevices with steel wool. Then, apply caulk or spackle over the steel wool to seal the hole against water, dirt and roaches. Cover any vents with screens.

Nearby trees and shrubbery

We humans lament the fact that food doesn’t just fall from the sky. Well, for outdoor cockroaches, it does! Fallen leaves are their bread and butter outdoors, so it’s no surprise they love to live around trees and shrubs. Anything that brings them closer to the outside of your house also brings them closer to the inside.

How they get in: While every type of cockroach is capable of crawling in, several types can fly! That means they not only sneak in at ground level, but at eye level, and from areas as high up as your roof.

Loose weatherstripping or warped concrete can create gaps under a door that cockroaches can sneak through at night.

Window air conditioning units can create a similar problem—those side panels often leave tiny spaces around the window frame (foam, steel wool or even a rag can help with this). And even thin gaps beneath shingles can give them access to your attic.

Pest control tip: Always cover doors and windows with screens if you plan to keep them open, especially at night. Most cockroaches are nocturnal and some are attracted to lights, so the nighttime is when they’ll be most active and most likely to fly in toward your lights. Use a door sweep, draft stopper or weatherstripping to stop bugs from crawling underneath.

Sewers

Truly the most revolting roach haunt: like horror movie monsters these bugs emerge from the dark sewers to crawl into homes and homeowners’ nightmares. They pick up dangerous bacteria from the sewage they’ve fed on and walked through and track it across every surface they touch.

How they get in: Once a roach has crawled out of the sewer, it’s already looking for a better place to hide. Cockroaches prefer dark, humid conditions with lots to eat, so if it thinks your house looks appealing, you bet it’s going to look for cracks or holes to climb through.

Pest control tip: Store your garbage can away from your house, if possible. (That goes for your compost heap, too!) Also make sure you’ve closed up any holes and cleaned the dead leaves from your gutters.

Where Indoor Roaches Come From

The Main Invaders: German cockroach, and brown-banded cockroach.

It’s easy to think about cockroaches invading from outside sources, but they often come from other people’s spaces and things.

Indoor, or “domestic roaches,” like the German cockroach prefer to live indoors. And they infest lots of human structures, not just houses. Unfortunately, these includes places you regularly bring things back from. And when you do, there’s a chance you could be bringing back roaches, too.

Where did roaches come from the last time you brought them in? Here are some of the places and things that might have given them their start:

2nd hand shops, hand-me-downs, and yard sales

“Another man’s treasure” isn’t the only thing hidden at yard sales and 2nd hand shops. All of those cardboard boxes that have been stored away for years are perfect habitats (and breeding grounds) for cockroaches.

How they get in: All it takes is to bring home one box of old magazines that’s also hiding some baby cockroaches for an infestation to spring up out of nowhere.

Pest control tip: Be very careful when buying things used, especially if those things come in old boxes or bags. You’re better off emptying them outside before you bring anything in.

Groceries and deliveries

Up next in the saga “Where Roaches Come From, Things You’d Rather Not Think About”—roaches living in grocery stores. At one store in Oregon, an inspector found “about 40 dead cockroaches” along the walls in the bakery section.

How they get in: It’s gross but they’re there, all right– and sometimes they hide out in the grocery bags and boxes you bring home or the containers you store food in. That could lead to an infestation in your car, too!

Pest control tip: Inspect your grocery bags before you move them from the cart to your car. Always make sure you open packages carefully, too. A warehouse full of cardboard boxes is prime roach country.

Indoor roaches can hitch a ride in your clothes

While I’m wearing them?! It’s rare but… yes. A cockroach could slip into the pocket of a coat as you sit or even climb into trouser cuffs. Roaches can also hide in purses, backpacks and shoes once you’ve set them down.

These bugs like worn, dirty clothes because of the smell of oils and skin particles that get stuck on them (not to mention the crumbs). Not only do dirty clothes attract indoor roaches (some roaches actually lay their eggs in them) but they can also be the reason they get into your house in the first place.

How they get in: If you’re not careful, a roach or two could hop into your basket at the laundromat and ride all the way home with you. If you visit another person’s house and they have an infestation, a cockroach can hide and become a stowaway in your coat or bag.

Pest control tip: Don’t leave your laundry bag or basket at a laundromat for longer than it needs to be there. Shake it out before you put your clothes back in, too. Shake out coats, bags and shoes if you think you might’ve been in a place with cockroaches.

How Both Types of Roaches Make Their Way In

Pipes

Here’s another one you probably don’t want to think about: cockroaches can enter buildings and move from room to room through the pipes.

That’s how they infest apartment buildings so quickly. Seeing one cockroach in the bathroom might seem like nothing but it could be a sign of many more hiding elsewhere.

Pest control tip: The simplest solution to this potential problem is to use covers on your bathtub and sink drains that have holes that roaches can’t fit through.

Why Are Cockroaches Trying to Get In, Anyway?

A roach infestation almost always comes down to two things: cockroach’s need for food and water, and oftentimes a third—warm areas like those inside your home. Roaches don’t need much to survive but they’re always on the hunt for their next meal.

To prevent cockroaches from even noticing your house, you have to know what attracts roaches and eliminate those things (like crumbs or dirty dishes). Then, you can use your new knowledge of how they get in to keep them out.

Conclusion

Where do cockroaches come from? From anywhere and everywhere that sufficiently meets their needs—and if you let them, they’ll make your home one of those places, too.

With the information in this article, our other guides to cockroach behavior, and a little determination, you can seal off your home from cockroaches, get rid of them if you need to. And never have to worry about them invading your life again.

Written by Andrew Martin. Reviewed by Rae Osborn, PhD.

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Sources

1. Ogg, Barb et al. (2006) Cockroach Control Manual. University of Nebraska Extension. Retrieved from https://lancaster.unl.edu/pest/roach/cockroach%20manual.pdf
2. Why do I have cockroaches in my home? (2016) National Pesticide Information Center. Retrieved from http://npic.orst.edu/faq/roach.html
3. Kivi, Rose. How to Seal Cracks for Home Pest Control. eHow. Retrieved from https://www.ehow.com/how_8044271_seal-cracks-home-pest-control.html
4. Rodriguez, Amy. What Kind of Mulch Has a Problem with Roaches? SFGate Home Guides. Retrieved from https://homeguides.sfgate.com/kind-mulch-problem-roaches–79886.html
5. Conger, Cristen. Ways to Get Rid of Roaches. HowStuffWorks. Retrieved from https://home.howstuffworks.com/home-improvement/repair/roaches-in-house1.htm

Cockroaches are widely known as small, ugly critters. But these ancient survivalists have adapted in amazing ways over hundreds of millions of years. Let’s take a look at some of the most important cockroach facts, and how they matter to you.

What Are Cockroaches?

Cockroaches are insects in the Blattodea order. They’re related to termites and once, deep in the distant past, the two insects shared a common ancestor. Scientists have discovered cockroach fossils that date back over 320 million years to the Triassic period and earlier. Talk about walking with dinosaurs.

There are well over 4,000 species of cockroaches living around the world. Most of them don’t live near or interact with humans but the few that do have become serious household and commercial pests.

Why are they called “cockroaches”?

“Cockroach” is actually an English mispronunciation of their Spanish name, cucaracha, that stuck. Have you heard the catchy tune “La Cucaracha?” It’s a Spanish folk song that’s been sung for centuries—and now you know what it’s really about.

The “Blatta” in Blattodea is Latin for “an insect that shuns the light.” Roaches belong to this family because they spend most of their time hiding in the dark.

Facts About Cockroach Biology

Life Cycle: How Cockroaches Reproduce

Cockroaches are egg-laying insects but they don’t lay their eggs like birds in a nest.

Female roaches lay eggs inside an egg case, called an ootheca. American cockroaches typically lay about a dozen eggs in an egg case while German cockroaches lay as many as 50 eggs in each. That’s a lot of baby cockroaches—up to 400 from a single female in her lifetime!

Male roaches of some species stick around to tend to the young after they hatch. Not only do the males scavenge food but they go as far as eating bird feces to take in vital nitrogen and bring it back to their offspring.

Why are baby cockroaches white?

Cockroach nymphs molt repeatedly as they mature. Each time, they shed their old exoskeleton and grow a new one. But during the short time in between, they appear white because they’re lacking that hard outer covering that darkens as it hardens with time.

What’s a cockroach’s lifespan?

Most cockroaches live for less than a year. The adult lifespan of a cockroach varies between species. An adult German roach only lives 20 to 30 weeks. However, an adult American cockroach can live for well over a year.

How do cockroaches breathe?

Cockroaches breathe very differently from humans. Instead of using their head to breathe, they breathe through tiny pores in their body segments called spiracles. A cockroach’s exoskeleton features a number of these holes that let them take in air and absorb oxygen directly into their organs.

This respiratory system gives them an amazing superpower— a cockroach can live a week without its head! (So when battling cockroaches, think the opposite of zombies—_don’t_ aim for the head!)

They also have an open circulatory system, which lets their blood travel through a system of connected spaces instead of on a closed track. A headless cockroach can still breathe and circulate blood; its undoing is actually that it can no longer drink water (or eat) without its head – thus dying from dehydration .

By Land or by Air: How Fast Are Cockroaches?

Cockroaches are crazy fast runners. Their powerful rear legs can propel them up to 1.5 meters (50 body-lengths) per second. Translated into human sizes and distances, that’s like running 200 miles per hour! (The Oriental cockroach is an exception—it’s noticeably slower than other species.)

Quite a few species of cockroaches fly but most of them do it awkwardly and seldomly.

For example, American cockroaches can fly but usually don’t. On the other hand, Asian cockroaches are relatively strong fliers. The unique green Cuban cockroach is probably the best flier of them all. It’s nicknamed the “banana cockroach” because of its tendency to fly around among the branches of banana trees.

Are cockroaches attracted to lights?

Some cockroaches avoid lights, hiding in dark places all day and scavenging at night. Others, however, are strongly attracted to lights. Flying cockroaches—like the smoky brown cockroach—are especially drawn to lights and, often, they fly through open windows toward TV screens and ceiling lights.

Can cockroaches swim?

A cockroach’s stick-like legs and delicate wings aren’t the ideal paddles for swimming through water. That doesn’t mean getting rid of one is as simple as flushing it down the drain, though.

A cockroach can hold its breath for up to 40 minutes! There’s a good chance it’ll come out fine at the other end and won’t mind a bit that it’s wound up in a sewer. After all, sewage is among the many things that make up a roach’s diet.

Why is it so difficult to crush a cockroach?

It turns out, a cockroach’s hard exoskeleton is also quite flexible or leathery. You can see the joints in it if you dare to look closely. Scientists studying these bugs used a machine to squish them with 900 times their body weight. They survived. More than that: they still ran at full speed, as if nothing had happened.

Where Cockroaches Live: Inside, Outside and Around the World

Most cockroaches live outdoors. They crawl among the fallen leaves on forest floors or build colonies inside tree hollows. They burrow, climb and fly to find habitats and, sometimes, that search leads them into buildings.

Are cockroaches really everywhere?

Cockroaches have a reputation for being expert survivalists but there’s one place on Earth they haven’t been able to colonize: Antarctica. Though it’s possible a few roaches have stowed away on ships and sailed the seas to that southernmost continent, they haven’t yet been able to adapt to its harsh, freezing conditions. But don’t ever count a cockroach out.

Do cockroaches build nests?

A cockroach “nest” isn’t like a bird’s nest. It’s typically just a hole, box or other dark, out-of-reach place where the roaches hide and reproduce. It will probably contain molted exoskeletons, droppings and a few dead roaches.

Some cockroaches live with ants.

Our homes aren’t the only ones cockroaches like to invade. There are at least 2 species of wood cockroaches that have been seen living with ants!

Researchers have found the western wood cockroach and the Boll’s wood cockroach living in anthills among the ants. It’s the nymphs of both species that seem to hide in the anthills during the day and leave to find food at night.

That’s despite the fact that cockroaches occasionally eat ants and other insects (even other dead roaches)!

The Cockroach Diet: Is There Anything They Won’t Eat?

Short answer: no. If it’s edible, a cockroach will probably eat it. Anything we eat—from meat and vegetables to sugar and grease—is fair game for a hungry roach.

Cockroaches are omnivores, meaning they eat both plants and animals. They’re also detritivores—organisms that eat decaying organic material. Rotten fruit, dead leaves and even animal waste are all on the menu for cockroaches.

It sounds gross, but a cockroach’s unpleasant eating habits make it an important part of its ecosystem. Roaches and other detritivores break down the dead plant and animal material and help return nutrients to the soil.

Can a cockroach survive without water?

Cockroaches can live a month without food. However, they can’t live a long time without water. Cockroaches are sensitive to dehydration and changes in humidity. That’s why they’re frequently spotted in bathtubs and sinks.

Cockroaches can go for a month without eating but they won’t survive longer than a week without water (depending on what they are feeding on, they may get some of their water from their food).

Cockroaches and Us: Friendly or Dangerous?

Although only a few cockroach species live among humans, those few can become major problems. The German cockroach is one of the most widespread household pests in the world, taking over city apartment buildings with ease. Once inside, roaches are destructive and potentially dangerous due to their ability to spread disease and filth.

Cockroaches can spread disease.

One of the more disturbing cockroach facts has to do with disease.

Because like rats and certain other kinds of pests, they can transmit diseases to people. Roaches crawl through sewers, drain pipes, gutters and piles of decaying material as they scavenge for food. If they make it into your house, they’ll spread the bacteria they’ve picked up on countertops, cooking surfaces and any food you’ve left out.

One of the adaptations that makes a roach so resilient is its body’s natural ability to produce antibiotics. That saves them from the harmful bacteria they could transfer to us.

Do cockroaches cause allergies?

The negative effects of roaches go beyond ruining food. Cockroach infestations can trigger people’s allergies. The main contributors to allergic reactions are the molted exoskeletons and roach droppings that they leave behind. People with asthma are especially sensitive to cockroach allergens.

Myths and Other Facts about Roaches

Can cockroaches survive a nuclear explosion?

Probably not. But cockroaches can survive intense levels of radiation.

“Rems” is the unit of measurement scientists use to describe radiation damage to the human body. 800 rems are fatal to humans. Meanwhile, cockroaches can withstand up to 100,000 rems. The thing is, a nuclear explosion creates a lot of heat too. Cockroaches are strong creatures but they can’t survive a temperature of 10,000 degrees Fahrenheit.

Do cockroaches like beer?

Cockroaches do like alcoholic beverages, especially beer! In a 2006 study, beer placed in a jar with bread attracted more cockroaches than any other bait. Roaches are drawn to beer by the sugar it contains, not for its alcohol content.

Do cockroaches crawl into people’s ears?

It’s extremely rare but… unfortunately… yes, they can. Your ears happen to be dark, humid and tiny—the 3 ingredients roaches look for in a habitat. Cockroaches may also see earwax as a food source. Again, cockroaches almost always stay away from people, so it’s probably best to forget about this fact as soon as possible.

Do cockroaches smell bad?

You already know about cockroaches’ poor hygiene. The places they venture don’t leave them smelling fresh. Cockroaches also produce chemicals that have a foul odor. When roaches touch food, they leave that smell behind—a good thing, since you definitely don’t want to eat a cockroach’s leftovers!

Do cockroaches bite?

Cockroaches can bite but they almost never do. There’s simply no reason for them to bite a person; they don’t feed on blood like mosquitoes and they’re not predators. On the fight or flight spectrum, cockroaches are very much flight when they come face to face with a towering human.

Conclusion

Despite all of their amazing adaptations, it’s important to get rid of cockroaches quickly if they’ve come into your house.

We’ve got all of the information you need to start an effective pest control plan, from where they hide to what they eat and how to keep them away for good.

Explore our in-depth guides to all things cockroaches and discover even more amazing cockroach facts while you learn how to keep your house cockroach-free.

Written by Andrew Martin, Reviewed by Helene Steenkamp, PhD.

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Sources

1. Cockroach (2020) Encyclopaedia Britannica. Retrieved from https://www.britannica.com/animal/cockroach-insect
2. Wilson, Tracy V. Cockroach Anatomy and Physiology. HowStuffWorks Animals. Retrieved from https://animals.howstuffworks.com/insects/cockroach1.htm
3. Jayaram, Kaushik and Robert J. Full (2015) Cockroaches traverse crevices, crawl rapidly in confined spaces, and inspire a soft, legged robot. PNAS. Retrieved from http://www.pnas.org/content/early/2016/02/04/1514591113.full.pdf
4. Wang, Changlu and Gary W. Bennett (2006) Comparison of Cockroach Traps and Attractants for Monitoring German Cockroaches. Environmental Entomology. Retrieved from https://academic.oup.com/ee/article/35/3/765/382141
5. Dell’amore, Christine (2010) Cockroach Brains May Hold New Antibiotics. National Geographic. Retrieved from https://www.nationalgeographic.com/news/2010/9/100909-cockroach-brains-mrsa-ecoli-antibiotics-science-health/
6. Father’s Day Pictures: All-Star Animal Dads (2012) National Geographic. Retrieved from https://www.nationalgeographic.com/news/2012/6/120615-fathers-day-best-dads-animals-pictures-science/
7. Disease Vectors and Pests (2009) CDC. Retrieved from https://www.cdc.gov/nceh/publications/books/housing/cha04.htm6. Retrieved from https://www.nationalgeographic.com/news/2012/6/120615-fathers-day-best-dads-animals-pictures-science/

You already know that roaches are a nuisance, and you may be aware of the serious health risks they pose. But what attracts roaches to your home or business? And more importantly, how can knowing that help you stay free of them – or even get rid of them once they’ve settled in?

Let’s dig in and find the answers…

What Attracts Cockroaches the Most?

Let’s make one thing clear. There’s probably no one thing you’re doing wrong that’s inviting roaches in. There’s also no single food, liquid, sight, or smell that’s making them target your home.

Cockroaches are easy-to-please, equal opportunity invaders attracted to any space that serves their needs. Once they find it, they’ll set up shop for good if you let them.

And no, you never, ever want to let them.

So what specifically are they looking for? For the conditions that assure their survival –

1. Food
2. Water and Humidity
3. Warmth
4. Safety
5. And sometimes… Light

You’ll notice that these just happen to be the same as our basic survival needs, too. When cockroaches are satisfied – hydrated, well fed, and comfortable – they spend most of their time hiding, reproducing, or (in a cockroach way) simply hanging out.

But when those needs aren’t met, they’ll begin a life or death hunt that may very well lead them to your home. Learning what they’re looking for will help you keep them out or kill them if they’ve already made their way inside.

Food

Like termites, mice, and other household pests, cockroaches have a relentless, never-ending drive for food. Attracted to strong smells, they seek it out and easily track it to its source.

Though it’s possible they have a preference for the same starchy, sticky, sweet foods that junk food-loving humans also enjoy – and might even have a soft spot for the yeasty taste of beer, roaches are anything but picky.

If there’s organic material in something, roaches will feed on it. Period. Meaning that glue, paper, animal waste and dead insects are on the menu along with every single food you eat – or the food you feed your pets.

Not only that, but thanks to millions of years of evolution, cockroaches have developed an extremely high tolerance for “toxic” foods and materials. Ever had food poisoning? Cockroaches don’t get it. Bacteria like that found in feces, rotting flesh, and garbage cans has no effect on them – and yes, they’re attracted to it.

Floors and counter tops offer roaches more food sources, along with more opportunities to attract them. Carpets collect crumbs that are usually too small for you or I to notice, and furniture can hide lots of specks of food that are perfectly accessible for cockroaches.

Storing paper in your attic or closet? It can attract and feed hungry roaches. They’ll nibble on starches, including wallpaper and book bindings, without any complaints.

With these decidedly undiscriminating bugs, “cockroaches ate my homework” is almost a valid excuse, though since they need very little food to survive, it would take an awful lot of them to do it.

Water and Humidity

While cockroaches can go for long periods of time without food, they can’t live very long without water, and some need water more than others. When cockroaches are able to find a source of water in your home, it’s a signal that conditions there may support them.

Perhaps the best-known of the water-loving roaches is the American cockroach which is fond of infesting sewers and storm drains, sometimes by the tens of thousands, or sometimes even more. In the structures we live and work in, they’ll be drawn to areas that are similarly moist.

The Oriental cockroach will be drawn to those areas too, and like the American roach, will seek out your basement or bathroom. Leave them a leaky pipe, a faucet or a water bowl and they’ll thrive. Throw in more leaking plumbing and they’ll follow your pipes through the walls, moving easily from room to room, or apartment to apartment.

Warmth

Warmth can attract roaches too. Many species are sensitive to cold and seek out warmth when outdoor temperatures begin to dip. When winter comes or a cold snap hits, they’ll be glad to find the warmth in your home and won’t be in any hurry to leave.

Warmth and humidity? Bingo!

Most roaches are especially attracted to warm and humid areas. Attics and closets are typically the worst-ventilated rooms in a house, making them prime cockroach habitats. Kitchens and bathrooms are also common cockroach habitats because of the presence of moisture and food.

Your home doesn’t have to be dirty to provide all the things cockroaches need. It just has to be warm and offer a few crumbs, a little standing water and some cracks and crevices for cockroach hiding places.

Safety

Ever been munched on by a rodent or a gecko? Or been drowned to death in a seasonal flood? It’s sometimes not a good thing to be a cockroach out of doors and your home can be the perfect refuge.

Even in a home with rodents or other critters (like your cat) that might kill them, houses offer unparalleled protection for cockroaches, with lots of tiny hiding spaces and comfortable areas to wait out dangers.

In fact, if you’re a German cockroach, which feels safest in snug spaces, human homes—along with their warmth and ample food supplies— provide a better habitat than any they could possibly find in nature.

Light

Like moths and certain other insects, a few cockroaches (but not most of them) are attracted to nighttime artificial lights. The male Pennsylvania wood cockroach is easily the best-known of them and bothers rural homeowners throughout mating season in the early summer. The Cuban cockroach, an even better flyer, annoys residents of southern states year-round.

How They Get In

Cockroaches are determined survivalists. And sometimes your home presents the ideal opportunity. Even roaches that prefer to live outdoors will seek out homes and businesses when necessary. And when they decide to, they’ll look everywhere for a way in.

Cockroaches can squeeze through tiny cracks and crevices in exterior walls to crawl into a building and take up residence inside the walls. Flying cockroaches have the additional advantage of flying or gliding onto your roof from tree branches. There, they’ll look for an attic vent or gaps between old shingles to come inside.

If you live in an apartment building, roaches can climb along pipes from unit to unit, spreading quickly through a building and bothering even the most careful tenants.

You might even bring a cockroach into your home accidentally. That pile of firewood under a tarp outside is the perfect hiding place for wood cockroaches. And it’s easy to carry a few surprise guests in with the wood.

Once they’re in, they’ll quickly find another hiding place (one that’s not on fire). The same goes for cardboard boxes you’d stored in the garage or shed: cockroaches love hiding in boxes and might take a short ride into your house.

Grocery stores and supermarkets are always at risk of cockroach infestations that could in turn affect your home. A roach could easily hide in the bag you’ve brought home then quickly scurry away to hide its egg case.

How to Avoid Attracting Cockroaches

What’s the most effective way to prevent cockroaches from entering your home?

Do the opposite of all of the things that attract them!

Clean on a regular basis, remembering to vacuum around furniture and sweep the kitchen floor. Seal or cover open food containers, including snack and pet food bowls, and check food items for infestation. Regularly clean and don’t leave dirty dishes in the sink. Repair any leaky pipes and make sure rooms are ventilated to reduce humidity and dry up standing water.

If you already have a cockroach problem, learn all about how to get rid of them and start taking action today. For large numbers of roaches, you should call a professional pest control service that can use specialized equipment and pesticides to eliminate the roach infestation.

Frequently Asked Questions

Written by Andrew Martin, Reviewed by Helene Steenkamp, PhD.

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Sources

1. Omg, Barb, et al. (2006) Cockroach Control Manual. University of Nebraska Extension.
2. Pappas, Stephanie (2018) Here’s Why Cockroaches Can Survive Just About Anything. Live Science. Retrieved from https://www.livescience.com/62093-why-cockroaches-can-survive-anything.html
3. Spector, Dina (2014) The Worst Way to Eliminate a Cockroach. Business Insider. Retrieved from https://www.businessinsider.com/how-to-get-rid-of-cockroachs–2014–3
4. Wolfe, Ireland (2017) How Can I Repel Roaches from My Bedroom? Hunker. Retrieved from https://www.hunker.com/13420962/how-can-i-repel-roaches-from-my-bedroom

Cockroaches pop up in homes and businesses around the world, drawn in part by the easy food sources they find in them.

Though cockroaches can live a long time without eating anything, they spend most of their time either eating or looking for food, and food drives a lot of their behavior.

That’s good news for you, because understanding what and how they eat is one of the keys to controlling them.

So what do cockroaches eat?

Let’s see…

What Do Roaches Eat?

Like certain other insects, cockroaches are omnivorous creatures, happily eating both plant and animal matter.

They’re also dedicated scavengers and some of the least picky eaters in the animal kingdom. Just about everything digestible by humans can be food for roaches – and a whole lot more. If it comes from an animal or plant, chances are that cockroaches will eat it, including food that we eat and a lot of material (like paper, clothing, books, and roach droppings) we don’t.

Cockroaches Eat Human Food, Everywhere They Find It

Cockroaches not only seek out human food, but seem to prefer some of the foods we like most.

They like greasy foods (like french fries and things covered in butter and bacon grease), starches (like breads and cereal), meat products, and sweets. They even like beer so much that it makes for a very nice lure in a homemade cockroach trap.

But the thing to keep in mind about roaches is that controlling them hinges less on knowing their favorite foods than on denying them any food at all.

Here’s the ugly truth about a typical cockroach diet – the where and what of stuff they like to eat:

Food on Kitchen Surfaces

With food and water everywhere, cockroaches love kitchen surfaces. Countertop crumbs make a great midnight snack and roaches will target any fresh or processed food items that you leave out.

A few pieces of pasta or some stray vegetables in the sink are sure to attract cockroaches, and provide plenty for them to eat. Even a small splatter around a stove burner can feed them, too. Unsealed leftovers are a treasure trove for roaches, as are dirty dishes.

Food in Your Pantry

Chips, cereal, sugar and other pantry items are like a steak dinner to a bunch of roaches. They’ll chew through paper, cardboard, or even thin plastic containers to reach the edible contents inside.

Keep in mind that as soon as a package of food is penetrated by a roach, it should be considered contaminated. These bugs come from all kinds of unpleasant places and pick up lots of bad bacteria along the way. They truly live in places most people wouldn’t even defecate in.

Crumbs on Your Floor

When dealing with cockroaches, you have to get down on their level–that means focusing on the floor.

Roaches spend most of their active time crawling around on the ground. Even flying cockroaches usually stick to their feet when they’re out in search of food.

Carpets collect food morsels like it’s their job. And hunting for crumbs basically is a roach’s job. Your carpet doesn’t have to be dirty to trap plenty of crumbs for a cockroach. With its strong sense of smell, a roach will find every crumb that’s there.

Your Pet’s Food

All things considered, pet food is pretty close to human food (at least from a cockroach’s perspective). As a bonus perk for roaches, pet parents often leave a bowl of dog or cat food out overnight. That’s like leaving a buffet out for pests.

Even if your hungry pet leaves an empty plate, crumbs and residue are enough to satisfy a cockroach.

Your Store or Restaurant’s Reputation

Kitchens are cockroach hotspots for a reason: there’s food everywhere! And what other places have food everywhere? Restaurants and grocery stores.

A roach infestation in a restaurant or market can be devastating to the business’s reputation. Unfortunately, commercial spaces deal with so much food on a daily basis that it may be impossible to keep everything spotless.

That’s why restaurants and grocery stores are at higher risk of having cockroach problems. If you’re a business owner, it’s wise to have a professional pest control company inspect and treat your property regularly to keep roaches out and bring customers in.

What Else Do Cockroaches Eat?

Cockroaches eat much more than just the things we consider edible.

Roaches’ ability to digest cellulose lets them eat all kinds of paper materials and even some clothing. They’ll nibble on newspapers, book bindings, documents and cardboard boxes. Some cockroaches eat the glue on wallpaper and stamps, too.

The American cockroach and other outdoor species of cockroaches feed on piles of leaves, twigs and dead trees. Just about any decaying organic matter is fair game. That also includes skin flakes, hair and fingernails.

Many other roaches feed on roach or other animal droppings. Between garbage, dead insects and feces, there’s just about nothing organic that cockroaches won’t eat.

How Can Roaches Eat so Many Disgusting Things?

Cockroaches enjoy a symbiotic relationship with some kinds of bacteria that live in their digestive systems. The bacteria use the roach as a host and in return, provide the roach with nutrients and help it to digest many nasty substances.

One study found that a huge part of the genome of American cockroaches is dedicated to metabolizing toxic or dangerous materials. Their bodies have adapted over millions of years to surviving in harsh conditions and eating whatever’s available.

Cockroach Pest Control – Time to Act Fast

Cockroaches can spread illnesses and contaminate food in homes and businesses. It’s important to have a solid pest control plan in place to protect yourself from these bugs.

Effective pest control starts with knowing where to find cockroaches. Focus your search on your kitchen and bathroom, looking for tiny crevices and in cluttered cabinets.

In the end, the best way to keep cockroaches out of your house is to clean diligently and make it as hard as possible for them to find food. If they can’t find dinner in your home, they’ll look somewhere else.

It’s important to get rid of cockroaches as quickly as possible. You can do it on your own with baits, natural pesticides and perseverance. Boric acid and food-grade diatomaceous earth are two products that you can use to kill cockroaches at home.

Or, you can call in the experts.

Remember, roaches are expert survivalists that spread quickly. They’re tough opponents! If you’ve seen more than a couple of roaches, it could mean a cockroach infestation, in which case your best bet is to hire a professional pest control service to get rid of them.

In the end, the best way to keep cockroaches out of your house is to clean diligently and make it as hard as possible for them to find food. If they can’t find dinner in your home, they’ll look somewhere else.

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Frequently Asked Questions

Written by Andrew Martin. Reviewed by Rae Osborn, PhD.

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Sources

1. Omg, Barb, et al. (2006) Cockroach Control Manual. University of Nebraska Extension.
2. Pappas, Stephanie (2018) Here’s Why Cockroaches Can Survive Just About Anything
3. Hadley, Debbie (2019) 10 Fascinating Facts About Cockroaches. ThoughtCo. Retrieved from https://www.thoughtco.com/fascinating-facts-about-cockroaches–1968524

Introduction

Where do roaches hide? It’s a tougher question than it seems.

Because cockroaches aren’t like most other creatures we encounter day-to-day. They’re tiny survival machines. And a big part of what makes them so tough to control or kill – or even spot before you’ve got an infestation – is their ability to hide so well. And do it so much.

Cockroaches can actually hide just about anywhere, so long as:

1. They’re near food.
2. They’re near water.
3. They’re sheltered from things they fear.

Add those things together and you’ve got a lot of cockroach hiding places, including some that wouldn’t necessarily occur to you.

But knowing what they need also makes finding cockroach hiding places easier. Because you know how to track them down – in bathrooms, kitchens, living spaces, and some of the less frequently used areas of your home.

Let’s take a closer look at this important first step in cockroach control…

Where Roaches Hide in Bathrooms

Where do cockroaches hide in bathrooms? With lots of water, even in places you might not guess, roaches flourish in bathrooms and find plenty of places to hide in them:

• Bathroom Sinks, Tubs and Toilets: Cockroaches love hiding under sinks, which are great sources of water. And they like drains, pipes, and the gaps in walls around pipes for the same reason. You’ll find them around tubs and toilets, which are particularly attractive not just for the water that drips, collects, and condenses around them. But for the soap residue, toilet paper lint, dead skin, and hair that accumulate nearby (and that they eat).
• Bathroom Tiles and Baseboards: If your bathroom tiles and the caulking around them are cracked, roaches may squeeze themselves into the empty space.
• Bathroom Cabinets: In bathroom cabinets, roaches may set up camp at the back, where they can snack on soap and toilet paper undisturbed.

Where Roaches Hide in Kitchens

Where do roaches hide in kitchens? With easy access to food, water, and warmth, you’ll find roaches hiding in obvious places, as well as areas you might not suspect:

• Kitchen Cupboards and Counter Tops: You’ll often find roaches hiding in kitchen cupboards, typically in the corners, or in the space between the shelves and wall where they’re difficult to see. Drawn to drips and puddled water, you’ll often find roaches hiding beneath dish mats and drying racks. And find them lurking all but invisibly in the gap between the kitchen counter and the cabinet below.
• Kitchen Appliances: You may find cockroaches hiding behind (as well as inside) every appliance in your kitchen: Refrigerators, dishwashers, dryers, washing machines, ovens, water heaters, coffee makers, microwaves, blenders, and toasters. Refrigerators are a favorite hiding place for roaches because the voids behind and underneath them are dark, warm, and full of water from condensation (thanks to the refrigerator’s motor). They’re also areas where food crumbs, spills, and bits of pet food typically collect. Likewise, the voids under and behind dishwashers provide lots of warmth, water, and spilled or forgotten food -and become roach infested quickly.
• Ovens and Stove Tops: With plenty of warmth and crumbs to eat, ovens and stove tops are a bonanza for roaches, and make prime cockroach infestation areas. If you have a stove with a top that flips up, you just might find cockroaches living there. They often set up shop inside the oven’s clock and electronics too, where the warmth and tight quarters make them feel safe.
• Pictures and Decorations: Cockroaches aren’t attracted to kitchen art, but they do like the voids behind pictures and other decorations. Even lifting a corner here or there can sometimes send them scurrying.

Where Roaches Hide in Work and Living Areas

Where do cockroaches hide where you work and live? “Everywhere” wouldn’t exactly be incorrect, but certain work and living “trouble spots” are worth a second look:

• Desk and Computer Areas: If you eat at your desk and your home is infested, there are probably cockroaches hiding out behind your computer. You may not see them during the day, but at night they’ll come out to snack on the tasty crumbs that have fallen into your keyboard.
• Furniture: Cockroaches are comfortable inside and underneath furniture. They may even lay their eggs there. On shelves, you can expect to find them behind whatever the shelf is holding, including books, pictures, and knickknacks.
• Pictures and Mirrors: Cockroaches will hide on the backsides of posters, mounted pictures, and wall mirrors. Less moisture-dependent than other species, Brown Banded cockroaches are particularly likely to be hiding behind pictures, especially those hung higher up, where the temperature is warmer.
• Closets: Cockroaches hide readily in closets, which are kept dark for long periods, and visited less frequently than other rooms. If you don’t see them on the walls, the ceiling, or the floor when you peek inside, look on the inside of the door, especially where it meets the wall, frame, or paneling.
• Walls, Wallpaper, and Electrical Covers: Roaches frequently wedge themselves into light fixtures and find their way inside electrical outlet covers. If there’s a tear in your wallpaper, cockroaches are happy to crawl right in behind it. And if there are holes, cracks and crevices, or air vents in your walls, cockroaches will find them and climb right in.
• Ceilings: Some species, most notably the Brown Banded cockroach, like to hang out on ceilings, especially in dark rooms. They wont be hiding when it’s dark, but if you turn on the lights, they’ll scurry into the molding or into cracks behind the trim.

Where Else Do Roaches Hide?

Where do they hide where you may not encounter them as much? And what overall are some of the worst trouble spots?

• Basements: Certain cockroaches in the United States, like American and Oriental cockroaches, can withstand cooler temperatures, and like to hide in basements. They both also live in sewers which connect to the basements of commercial spaces, such as restaurants. If you find a cockroach living in your basement, it’s probably one of these.
• Attics: Some species may hide out in attics, especially if there are leaky pipes to drink from, and cardboard boxes to use for food. When they aren’t living in the ceiling itself, they wedge themselves behind baseboards. Or in the cracks where baseboards meet. Or behind door and window trim.
• Clutter: Clutter may be an eyesore to you. But for cockroaches, it means food and protection. They not only hide in it, but find things to eat in it. And if it holds any newspaper, cardboard, or paper of any kind, they’ll eat it, including the glue that holds cardboard boxes together and seals envelopes shut.
• Trash: Trash is a cockroach’s favorite thing and they’ll hide in it whenever they find it. Look for cockroaches wherever trash accumulates, and wherever it’s been, including the bottoms of trash cans, and the walls, electrical outlets, and baseboards that are behind them.

Getting Rid of Cockroach Hiding Places

Finding cockroach hiding spots is a start. But you’ll want to get rid of them and keep them from infesting those areas again. We tell you elsewhere how to find them, and how to kill them, but here’s how to begin making your home a much less comfortable place for roaches to hide:

• Get Rid of Easily-Accessed Water: Whether it’s drips, drops, or puddles, roaches need water to survive, and you’ll want to find out where they’re getting it. Find water, and if your home is infested, there are sure to be roaches hiding somewhere nearby. Seal any leaks you find, clean up standing water, then wrap and seal exposed pipes.
• Remove Food Sources: Where do roaches hide when they can’t find food? To somebody else’s house. Clean up spills and crumbs everywhere, including hard-to-reach areas under refrigerators and stoves. Then keep food sealed and stored in air-tight containers.
• Seal Up Your House: You may not be able to make your house totally inhospitable to roaches (after all, you like warmth and comfort, too). But you can do things to keep them out, like creating barriers at entry points that keep them from getting inside. Seal holes and cracks in your outside walls, and fill gaps along window sills and door frames.

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Frequently Asked Questions

Conclusion

Where do roaches hide? In all the places you don’t want them.

If you suspect cockroaches in your house, it’s critical to find out where they’re lurking. And take steps to get them out. It’s equally important to find out how they got in, so you can stop them from getting in again.

With just a little know-how about pest control, the next time a cockroach hides in your home, you’ll be more than ready to find it. And make that visit its last.

Cockroach Facts is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.

Introduction

When you find yourself face-to-face with a roach infestation, certain discoveries are unpleasant, while others are just plain… awful.

Roach droppings for most of us fit right into the awful category. And if you’ve been unlucky enough to find the stuff somewhere (like where your family eats and sleeps and lives), you’re probably not only thoroughly disgusted. But angry. And more than a little confused.

After all, roaches haven’t just been attacking your home. They’ve been using it for a toilet. And if there are enough droppings around that you’ve actually seen it (think for a moment about all the droppings in places you can’t see), the roaches have been winning. That is, until right now.

If you can manage to hold your nose to the end of this article, you’ll not only have a better idea of how and why roach droppings got into your home. But how to get rid of it, along with all the roaches too. Ready?

What’s Inside Cockroach Droppings

Cockroach droppings are made up of all sorts of things that roaches have digested: Food from your cupboards, counters, and drawers. Garbage. Rotting flesh. And dead insects, including the carcasses of other cockroaches.

Cockroaches don’t pee (a not-so fun fact), but instead secrete solid and semi-solid waste. All of which varies in appearance, depending on the size, age, and species of roach you’re dealing with.

What Cockroach Droppings Look Like

What does roach feces look like? What you find will probably look something like this:

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Generally speaking, cockroach droppings are dark brown or black pellets. They’re either roundish chunks or oval-shaped, and much of what you find will simply appear as smears and stains on the surfaces that cockroaches have been crawling over.

Of course, before a full-blown infestation, roach droppings will be so minimal and scattered that you may not even see them. While on the other hand, during a large infestation they’ll be almost impossible to miss, along with other nasty cockroach stuff like egg cases, discarded shells, and cockroach body parts.

Since you’ve managed to make it this far, let’s take a closer look at some of the tell-take signs that the leading culprits leave behind.

Droppings From Large Cockroaches

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If there were a single rule of thumb that helped identify roaches by their frass (the more proper name for insect droppings), it would be this: Larger roaches make bigger droppings. American, SmokyBrown, and Oriental cockroaches are all considered larger species. They are usually more than 1 inch long. They produce solid, cylindrical feces that can be as large as a grain of rice.

If you were to look closely, you’d see ridges running from one end of the dropping to the other – giving it an appearance sort of like a fennel seed.

Do you have mice, too? Other than cockroach frass being smaller, this is one of the main differences between mouse droppings and those of cockroaches. Because mouse droppings will be mostly smooth. It will also be pointed at each end (unlike roach feces which is blunt), and sometimes has small hairs from the animal’s body stuck to it (which roaches of course don’t have).

Droppings From Small Cockroaches

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The droppings from small cockroaches is different. Not just in size, but in shape. Small species like Brown-Banded and German cockroaches leave behind tiny brown or black specks or stains. The droppings can look like coarse ground coffee or grains of coarse black pepper, while the stains can be inky, smeared, or raised.

If you had to distinguish German cockroach frass from that of Brown-Banded cockroaches, you’d find that German roach frass was moister (more smeary), due to the German roach’s preference for wetter environments.

Frass From Baby Cockroaches

Baby cockroaches (called nymphs) produce feces similar to adult roaches, but smaller. The droppings of large cockroach nymphs are small, cylindrical, and ridged, while those of small cockroach nymphs are minuscule brown or black specks.

Does Roach Feces Have a Smell?

Does cockroach feces have a smell? Absolutely. It stinks. It also has an acrid, oily odor, but what your nose smells is only half the story. Because the odor roach droppings give off harbors a sinister secret.

It conveys signals to other cockroaches that they’re around, provides a trail for other roaches to follow, and ultimately helps them find each other.

Which means that the smell of roach excrement isn’t just bad. It’s actually attracting more roaches.

Can There Be Droppings But No Roaches?

In a word, yes. There can droppings from roaches that once lived inside your house, but have died or somehow left (like from a past extermination). Unless a roach or other insect eats it, or you knuckle down and clean it up, the droppings will just sit there, slowly decaying and sometimes molding for many, many years.

One way to tell if you have an active cockroach infestation is to clean up all the droppings you’ve found, then monitor your home to see if more appears. If it stays roach dropping-free, you probably don’t have a current infestation. If you find that more droppings appear however, it means it’s time to get those roaches out.

Can Cockroach Droppings Make You Sick?

Even if you don’t have an active infestation, roach feces is a bad thing to have around. Can roach it make you sick? Yes, it can.

Cockroach droppings (and shed skin) contain proteins that trigger allergies and asthma attacks in some people. They may even cause children to develop asthma. These proteins can linger in the home even longer than the feces themselves, remaining dangerous for years after the roaches themselves have gone.

Not only that, but cockroaches’ eating and living habits bring them into contact with bacteria, mold, fungi, viruses, and worms that they leave behind in their feces.

Couple that with the fact that roaches go to the bathroom literally everywhere, including in the food that you and your family eat.

Let that sink in for a moment. It means that if cockroaches are living anywhere inside your home, there’s a good chance you’re ingesting cockroach excrement.

Now consider this: Food poisoning can be caused by roach feces. And if the harmful bacteria that’s sometimes carried by cockroaches spreads from your digestive system to your blood stream, it could – potentially – even kill you.

How to Clean Roach Droppings

Cleaning feces and cockroach smear marks is nobody’s idea of a good time. But with your family’s health and safety on the line, you’ll be more than glad you did.

Suit Up

Suit up before you get to work. Old clothes are fine, and put on a pair of gloves. Purchase a protective face mask or a respirator to reduce exposure to potential airborne allergens.

Vacuum

Plan to vacuum first, using the vacuum to remove loose, dry roach droppings that have accumulated over time. Since vacuuming can stir up allergens, you’ll want to use a vacuum with a HEPA filter to keep the air around you safe. If a HEPA vacuum isn’t available, soak the feces in disinfectant spray instead, then wipe it up by hand.

Clean

Everywhere that you find roach feces will require different cleaning methods.

• For carpets, start with the vacuuming tips above (you can scrape off any dried, stuck-on cockroach pellets before vacuuming to get most of it off first). Next, either use a carpet detergent (read the label to determine how much to dilute it) or mix up white vinegar, dish soap, and water (one teaspoon each of vinegar and soap to a full spray bottle of water) and spray the area. Scrub to work the soap into the carpeting. Let it fully dry before vacuuming again.
• On walls and hardwood, tile, cabinets, or vinyl flooring, choose a disinfectant spray that is safe for the material. Spray the affected area and leave it on for the recommended amount of time, then scrub to get out the stains.
• If you find roach droppings on your clothes, first scrape off any dried there, then treat stains and wash in the warmest water that is safe for the fabric.
• Cockroaches can also infest mattresses. As with clothing, the first step is to scrape off the dry feces. Next, mix disinfectant soap and warm water in a spray bottle, spray the area, and scrub with a coarse sponge. Spray again with just water to rinse the soap out, then let the mattress air dry.

Dispose

Since cockroach feces is so unhealthy, you’ll want to wash or throw away anything that comes into contact with it. When you’ve finished the job, be sure to wash (or throw away) your gloves and work clothes, and dispose of rags and vacuum bags, preferably in sealed plastic trash bags that animals or other people can’t get to.

Suggested Products If You Have a Cockroach Problem

To Find Cockroach Hiding Spots and Kill Them Quickly When You Have Just a Few

Recommended for all cockroaches

To Kill Cockroaches Inside Your Home When You Have a Serious Problem

Recommended for German cockroaches and Brown banded cockroaches, as well as American cockroaches (Palmetto bugs, Water bugs, Tree roaches, Sewer roaches), and Oriental cockroaches when they enter in large numbers.

To Kill Cockroaches Outdoors Before They Have a Chance to Get Inside

Recommended for American cockroaches (Palmetto bugs, Water bugs, Tree roaches, Sewer roaches), Oriental cockroaches, and Smokybrown cockroaches.

Next Steps

Cleaning up roach debris is the first step to living cockroach-free and ultimately reclaiming your home. The next steps are to get the roaches that have set up residence, and to keep them from coming back. You can attempt to do that by yourself (and we’ll show you how here), or call in a professional pest control service to do it for you (we’ll show you how to do that here).

Either way, by knowing what to look for and knowing what to do, you don’t have to live with the stains, bad smells, and health risks of cockroach droppings even one more day, so long as you take action.

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Frequently Asked Questions