You hoped you’d never have to deal with water bugs in your house. But, now, you’ve discovered them crawling around in your kitchen, your bathroom, your basement.

Some folks might tell you to shrug them off as a nuisance, something to get used to seeing. But water bugs are dangerous pests. They contaminate your home and spread disease. And your water bug problem will only get worse if you leave it alone.

In this article, you’ll learn what brought water bugs into your house, what they’re doing behind the scenes and, most importantly, how to eliminate them.

Ready to get rid of water bugs in your house for good? Let’s get to work!

What are Water Bugs? Are They the Same as Roaches?

Two-grid illustration of 2 roaches - an American roach and an Oriental roach - considered to be house-infesting water bugs.

Water bugs are extremely common pests, especially in the southern U.S. They’re the big, brown or black bugs that probably first appeared in your kitchen, laundry room, bathroom or basement.

Even if you haven’t seen one before now, you’d probably heard about them from neighbors or friends who had already dealt with them.

What you might not have heard is that aside from a certain pond dwelling creature called the Belostomatidae (or Giant Water Bug) which rarely enters homes, water bugs and roaches are the same thing. Specifically, water bugs are one of two species of cockroaches: American roaches or Oriental roaches.

Note: The smokybrown cockroach which some people also call a water bug, is not discussed below. You can read more about it here.

American Roaches

American cockroaches are the biggest roaches you’ll encounter at home, measuring in at up to 2 inches in length. They’re reddish-brown, with flat, oval-shaped bodies and long antennae that make them look even larger. Both males and females have wings, with the male’s being somewhat longer.

Oriental Roaches

If you’re seeing big, black water bugs in the house, you’re dealing with Oriental cockroaches.

These roaches are 1 to 1.5 inches in length and often a bit rounder than other species. An adult Oriental roach sports a shiny black color. While a male usually has short wings that cover about 2/3 of its body, a female’s wings are tiny and rudimentary. Neither sex can fly.

Water Bug Nymphs

Comparative illustration of American and Oriental cockroach nymphs

What if you found small water bugs in the house? They could be nymphs—baby water bugs.

  • Baby American roaches look like smaller versions of the adults, with the same reddish-brown, oval-shaped bodies—but absent any wings.
  • Oriental roach nymphs tend to be lighter in color than the glossy black adults. They might appear golden or copper-colored but will still have the stout, round shape of the adults. Oriental cockroach nymphs also do not have wings.

There is another possibility to consider…

Water Bug or German Cockroach?

German cockroach nymph, adult, and egg, compared to a penny for size

If the bug isn’t a nymph, it could be a German roach—perhaps the only discovery worse than baby water bugs.

  • To tell a German cockroach from a water bug nymph, look for its light tan color and the dark pair of parallel stripes that run down its back.

American Roaches, Oriental Roaches and Your Home

Both American and Oriental roaches are primarily outdoor species. So what are they doing in your house?

These insects prefer to live among wet undergrowth and decaying organic material. Neither of these insects spends any time in the water (unless they have to); their nickname merely refers to their constant need for moisture.

They inhabit forest floors, the hollows beneath rocks and the landscaping around homes. Flying American roaches might live inside tree hollows or beneath loose tree bark.

In urban environments, they hide in dumpsters, gutters, sewers and storm drains. They’ve been discovered in septic systems and observed pouring in the thousands from city manholes.

The scenes in these places are grim: multitudes of water bugs thriving in the moisture, laying egg sacs that will increase the colony’s size exponentially. They’re surrounded by their own droppings and discarded exoskeletons, on which mold grows and adds to the already-disgusting stench.

What Causes Water Bugs in the Home?

Cartoon illustration of a small cockroach sneaking into a home's open window during the night.

Cold weather often drives water bugs indoors. Although Oriental roaches can tolerate cooler temperatures than other species, they also look for warm harborage as the weather changes.2

Extended periods of hot, dry weather can also make things uncomfortable. Without ample moisture in their environment, water bugs will dehydrate quickly.

When heavy rains flood American cockroach habitats, these water bugs might look for dry shelter in a nearby basement or crawl space. Entire colonies sometimes migrate together. They’ll follow the plumbing into the walls or climb into trees and glide onto the roof.1

How Do Water Bugs Get Into the House?

Water bugs often live around human dwellings. The area around your home is full of potential hiding places. Excessive watering makes mulch and garden soil perfect habitats for water bugs. Unruly piles of firewood store moisture and make ideal cockroach breeding grounds.

We’ve already mentioned that Oriental roaches are flightless. They also can’t climb smooth, vertical surfaces, so they’re usually going to search for entry points at ground level. Water bugs exploit openings in exterior walls, torn window screens, gaps beneath doors and other cracks and crevices.

These insects could follow your TV cable straight from an exterior wall to your living room. A water bug can even climb up the pipes of a rarely-used toilet or shower where the P-trap has dried up.

American roaches can glide from tree branches or tall shrubs onto a windowsill and climb in through a torn screen. They can even sneak under loose roof shingles to enter homes.

Note: There’s always the possibility that you’ve brought them in accidentally. Carrying a few logs for the fire into the living room or a box of tools from the garage into the kitchen might bring these unwanted pests inside, where they’ll find warmth, plenty of hiding places and the smell of food.

What Water Bugs are Doing in Your House

Illustration of a nest of Oriental cockroaches on the floor of a basement, egg case in the foreground.

Once a water bug finds a way inside, it starts searching for its basic survival needs: food, water and a dark, damp place to hide.

Within the walls are endless crevices where water bugs can hide and multiply. As they scavenge each night, they leave pheromone trails to help other roaches follow their routes to food.

Meanwhile, they contaminate your food with dangerous bacteria and leave excrement all around your kitchen and bathroom. They might feed on old documents, paper keepsakes or family photos. And they’ll lay eggs—dozens of them—deep in the walls or behind cabinets and appliances.

These insects multiply rapidly. One water bug could lay over 150 eggs in a year. Before you’ve even noticed them in your home, the infestation could number in the hundreds. And even as you spray or smack every water bug you see, plenty of eggs are waiting to hatch and make matters much worse.

Effects of a Severe Water Bug Infestation

Leaving water bugs alone is not an option. Playing whack-a-mole with one bug at a time or trying to pretend they’re not there gives them free rein to keep breeding and spreading.

You’ll see more and more water bugs, you’ll spend more and more time trying to squash and spray while these pests continue to spread bacteria and put your family at risk of stomach illnesses, allergies and asthma attacks.

When a roach infestation grows out of hand a home becomes unlivable. At that point, it’s up to a professional exterminator to save it.

How do you get rid of waterbugs in your house without an exterminator? And begin to do it today?

With “CIAO.” A system for getting rid of water bugs in house and apartment structures permanently.

Getting Rid of Water Bugs with CIAO: Clean, Inspect, Attack, and Outsmart Future Water Bugs

Water bugs aren’t easy pests to get rid of. That’s why professionals use an approach called IPM (Integrated Pest Management) to control them for the long term. CIAO, which stands for Clean, Inspect, Attack, and Outsmart is your at-home attack plan for putting professional IPM strategy to work.

Using CIAO, you’re going to:

  1. Clean your home, depriving water bugs of anything that could sustain them.

    Water bugs need food to survive and often find plenty to eat in the crumbs and clutter we leave behind. You can starve water bugs out by thoroughly cleaning your home.

  2. Inspect your home for areas water bugs are most active.

    As you clean, you’ll want to inspect for signs of water bugs, too. You’ll use the evidence you spot and uncover to create a battle plan.

  3. Attack water bugs in ways that substantially reduce their numbers.

    It’s payback time. You’ll use state-of-the-art tools and techniques to hit water bugs hard and drastically reduce their numbers.

  4. Outsmart water bugs that want to re-infest your home.

    Even after you’ve reduced their numbers or even eliminated them entirely, water bugs may still come back. In this final phase, you’ll take steps to anticipate water bugs’ next moves and beat them back before they have a chance to invade again.

Putting the CIAO System to Work

1. Clean

Cleaning is the most important first step you can take, and the keystone of the rest of the system. Put on some comfortable, old clothes you’re not afraid to get dirty. Grab a knee pad or use a folded towel to make yourself comfortable while you peer with a flashlight under appliances and furniture. You’ll need at least one large, sturdy garbage bag and your vacuum cleaner.

You should also grab a notepad and pen to write down each place where you find evidence of roaches. While we’ve listed inspection as the next step, you should always start inspecting while you’re cleaning to get the best high-level picture of the problem.

You’re going to start by emptying all of the cabinets, drawers or shelves in the rooms where you’ve seen water bugs. If you’re emptying kitchen cabinets, discard any food or ingredients that water bugs might’ve gotten into. If you’re cleaning the bathroom, throw away your toothbrush or disinfect the body and replace the head.

Put all utensils, pots and pans, personal hygiene items, toys and other sensitive objects aside to clean later. Water bugs might’ve touched them.

As you clean, remember to make a list of all of the places where you find roach droppings (which look like coffee grounds) dead roaches or discarded exoskeletons. You might also notice a musty stench emanating from areas with high roach activity. Give a quick description of each find so you can reference it shortly, when you’re setting traps.

Once you’ve emptied out your things and recorded the evidence, use the vacuum to suck up all of it—dust, crumbs and, potentially, dead water bugs and their eggs or exoskeletons. If you can safely pull the fridge or other appliances away from the wall, vacuum behind and under them, too.

Then, use a disinfectant spray or wipes to sanitize surfaces and remove the roach’s communication trails.

Find even more tips for sanitizing after water bugs in our Roach-Free Recipe.

2. Inspect

You’ve already started to make a list of the cockroach hotspots you found while cleaning. Now that everything’s cleared out, look for the holes and cracks where water bugs could hide and travel. Keep your eyes open for more droppings and dead roaches, too.

It’s important to check exterior walls, windows and doors, too. You’re looking for openings just half an inch wide through which water bugs can crawl. Pay close attention to areas near the ground where both Oriental and American roaches are most active.

Later, you’ll seal up these entry points. First, though, you’ll make these hot spots your targets for sticky traps.

Sticky traps—a.k.a. insect monitors—will show you where the insects are most active and help you estimate the size of the infestation. With these monitors in place, you’re also getting a head-start on the next step—attack. Sticky traps are your first wave of attacks, letting you start eliminating water bugs even as you gather information.

Place a sticky trap near each location you’ve written down on your notepad. You should also place sticky traps in other high-risk areas: behind the fridge, along basement walls, under pipes and near appliances.

Learn how to get the most out of sticky traps in our guide to inspecting for roaches.

3. Attack

There are lots of purported home remedies to kill water bugs instantly out there, from bleach to baking soda. We’re going to focus on the four tools the pros choose to use water bugs’ behavior against them:

  1. Baited traps
  2. Gel bait
  3. Insecticidal dust
  4. Insect growth regulator (IGR)

Deep cleaning has already removed the insects’ easiest food sources, starving them out. In addition, you’ve started catching the desperate pests with sticky traps.

Now, apply powerful gel bait to cracks, crevices and other hotspots you’ve identified to target the colony at its core. Gel bait is especially effective because the poison spreads from one roach to others as the insects return to the nest to die. Water bugs multiply fast; gel bait lets you fight back faster.

Insecticidal dust like boric acid, silica, and diatomaceous earth are better for less precise, harder-to-reach areas because it’s long-lasting and easy to spread widely.

Apply a thin layer of dust in places like wall cavities and floor voids. The deadly dust particles float through the air, stick to surfaces and kill roaches by dehydrating them. A silica dust like CimeXa is very low in risk to humans but extremely effective at killing water bugs. You can even mix in some powdered sugar to attract the bugs to it.

An IGR is an extra line of defense that prevents roaches from producing offspring. While traps and insecticides kill the adult water bugs, an IGR stops the colony from growing behind the scenes.

Read our guide for all the details on killing water bugs in your home.

4. Outsmart Them (How To Keep Water Bugs Away)

The final step in this water bug elimination plan is a long-term effort: preventing water bugs from getting back inside.

You know that a water bug wants a dark, warm, protected environment with plenty of moisture and easy access to food. Now, outsmart these bugs by closing all of their entry points, sealing up your food and reducing damp areas wherever possible.

Use steel wool and insulation foam to plug holes in your walls and floors. Repair window screens and door frames so there are no spaces for bugs to enter. Fix dripping faucets or leaky pipes that become water sources for roaches. Use fine mesh drain stops in the bathroom, especially in sinks and showers that you rarely use, and be sure to mop up standing water.

Finally, place a few glue traps in previous water bug hotspots to monitor for signs of new activity. You can also dust into walls, floors and other spaces before sealing up holes. As long as it stays dry, dust can kill roaches for over a year.

Get more tips for stopping roaches that invade homes in our guide to preventing roaches with exclusion.


As you read this article, the water bugs in your house were hiding safely out of sight, waiting until night to begin scavenging again.

They don’t know that you’ve learned all about their behavior and how to use that knowledge to eliminate water bugs. In-house[1] pest control methods, like the ones we’ve described in our “Ciao, Roaches” plan, give you the power to start clearing your home of pests today.

You’ve got this!


  1. Barbara, Kathryn A. (2014) American cockroach. University of Florida Institute of Food and Agricultural Sciences. Retrieved from
  2. McCanless, Kim (2017) Oriental cockroach. University of Florida Institute of Food and Agricultural Sciences. Retrieved from

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