Waterbug vs. Roach: What’s the Difference?

Cockroaches and waterbugs, their appearance, diet, habitat, and ways of getting rid of them.
Phyllis McMahon
Phyllis McMahon
Research Writer
Phyllis teaches English Literature at a local college and loves writing in her free time. She’s also a great cook – her British beef Wellington is something the best res read more
Reviewed By
Chas Kempf
Chas Kempf
Expert Consultant
Chas works in a professional pest control company and knows all the nuances of this job. Also, he’s a fantastic tennis player and loves to organize BBQ parties for his fam read more
Last updated: August 23, 2023
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If you have an infestation, you can easily get rid of it once you understand the kind of pest you are dealing with. Cockroaches and waterbugs are insects that can be hard to differentiate because of their similar appearance. The oriental cockroach, in particular, is often mistaken for a waterbug because it lives near damp areas.

So, what’s the difference between waterbug vs. roach? You will be surprised to learn that, contrary to what most of us think, cockroaches and waterbugs have little in common. They vary in their feeding habits, biology, appearance, and habitats, among other key differences.

Our article covers these two insects and explains how you can tell one from the other and how you can get rid of waterbugs and cockroaches.

What Is a Waterbug?

Waterbug vs. Roach: What’s the Difference?
You can meet these bugs near water, probably motionless, waiting for a prey.

Waterbugs, also known as true bugs, are in the suborder Heteroptera order of insects that has a proboscis for sucking liquid from prey. The proboscis is a long mouthpart that resembles a long tube.

Roach vs. waterbug pictures indicate that they have different sizes and colors. Waterbugs are brown or grayish and their length is approximately 2 inches. They are aquatic insects with paddle-like legs for swimming.

Cockroach vs. Waterbug

Waterbug vs. Roach: What’s the Difference?
Cockroaches are generally larger than waterbugs, and they have longer, narrower bodies.

Cockroaches are brown or red in color. Amid our research, we found that you can mix up a german cockroach with a waterbug. The most notable difference between a German roach vs. waterbug is that waterbugs are hunters that live in water, while cockroaches, including the German species, are scavengers that typically live on land. Also, roaches look like beetles and have much longer antennas than waterbugs. Additionally, cockroaches are generally smaller in their length, ranging from 1 to 1.5 inches, although some larger cockroaches can be as big as water bugs.

Do you see familiar characteristics of a German cockroach? Then with no hesitation check the best German roach killers that are not toxic to people and pets, in order to prevent roach-related health concerns such as asthma episodes.


For wood roach vs. waterbug, one of the similarities the two insects share is a flat body that is oval in shape. Otherwise, you can easily identify them by their distinct features. Waterbugs have a proboscis to pierce prey and suck out fluids and flattened hind legs that resemble paddles to move through water, while cockroaches have two long antennae, long legs, and chewing mouthparts.


Waterbugs live in water whereas cockroaches live in dark, warm, and wet areas on land, with the favorite habitat depending on the species. For instance, the oriental cockroach lives in cellars, basements, and sewer drain and the German cockroach prefers furnaces, kitchen sinks, and bathroom sinks. On the other hand, if we compare wood roach vs. waterbug, the former lives outdoors in dead trees and wood piles while the latter is an aquatic bug that hunts in water.


Waterbug vs. Roach: What’s the Difference?
Waterbugs and roaches have their diet according to the environment they live in.

Another difference between a cockroach vs. waterbug is in their feeding habits. Waterbugs are predators that live and hunt in water for prey that includes small amphibians and fish. They use their tube-like mouthpart to inject an enzyme that dissolves the insides of their prey and sucks the fluids.

Roaches eat everything they come across, including scraps of food, insects, wood particles, algae, and decaying leaves. Water is important to both the American roach and the waterbug. Although roaches do not live in water, they live near sources of water such as bathrooms and kitchens.

Bite Risk

Waterbugs have a proboscis that they use to bite people. Although cockroaches do not bite people, we recommend protecting yourself with the best roach bombs and foggers because roaches can transmit diseases. According to the Environmental Protection Agency (EPA), you should ventilate the treated area after fumigation to prevent exposure to the pesticide.

What Causes Waterbugs in the House?

A significant difference between waterbug vs. roach is that cockroaches are the pests that are most likely to invade your home in search of food, water, and shelter. As nocturnal pests that are also aquatic, it is rare to find water bugs in your house. However, light attracts them, and they might accidentally get in the house if you turn on your porch light at night and your house is close to a body of water.

Do Waterbugs Bite? What About Roaches?

Unlike cockroaches, water bugs can bite humans if you don’t handle them properly because they have a mouthpart that can pierce the skin to feed by sucking the liquids.

Diseases & Problems

The safer of the two insects is the waterbug. Roaches, including baby roaches, pose a greater risk because they are pests that spread bacteria and contaminants that can cause allergies and diseases. This is largely to a cockroach’s filthy feeding habits which include rotting food. Waterbugs mainly eat other insects and larger species may also eat small fish and amphibians.

How to Get Rid of Water bugs and Cockroaches

Waterbug vs. Roach: What’s the Difference?
Glue traps, bait stations, liquid concentrates, and many more methods are all useless unless you keep your house clean all the time.

Find the best roach killer that can also help you to get rid of waterbugs. There are several products, such as Hot Shot Fogger With Odor Neutralizer, that kill on contact and last for up to 2 months. You can safely use it in apartments to eliminate cockroaches, as well as in boat cabins to get rid of waterbugs.

Below are other ways to prevent or manage an infestation.

1. Clean up and hope they leave.

Pests such as cockroaches and water bugs are nocturnal. However, cockroaches prefer living indoors for shelter as well as food and water. They hide in cracks and crevices in dark, warm, and moist places and then come out at night to search for food scraps. Keeping clean surfaces and eliminating their food source by sealing your food and emptying the trash regularly can deter them. Keep your sinks and surfaces clean and dry since roaches are also drawn to moisture.

2. Use baits or natural cockroach killers.

How does boric acid kill roaches? It works by damaging their digestive and nervous system. However, it might be hazardous to pets if they inhale or ingest substantial amounts of boric acid over a long time. Bait traps such as Combat Max 12 Month Roach Killing Bait provide safer extermination methods.

3. Call in backup: hire a professional.

Considering the disease-causing allergen content in cockroach feces, you need to get rid of roaches as soon as you notice them before they multiply and fill your house with germs. If the methods you have tried have failed, it’s okay to call in a professional who will have a solution that is best tailored to your home.


Can Waterbugs Infest Your House the Way That Indoor Roaches Do?

Roaches breed in large numbers, and your house serves as a source of shelter for them. If you have an infestation, the most likely culprit is cockroaches, not waterbugs that prefer living outdoors in water where they can hunt for prey.

Can Waterbugs Come Up Through Toilets?

Although it’s not common for waterbugs to enter your home, if you live near water and have a toilet that is not used and flushed regularly, water bugs can come up through the plumbing pipes in the toilet.

Is It Normal to Find a Waterbug/Roach in Your House?

Now that you are familiar with water bug vs. roach pictures and key differences, you are aware that there is little chance of finding a waterbug in your house because they spend their time in water and feed on aquatic insects, fish, and amphibians. On the other hand, your house will appeal to cockroaches as a plentiful source of food because they eat everything, from crumbs of food to wood fragments and decaying matter.

Final Thoughts

From now on you know what’s the difference between water bug vs. roach. The water bug is bigger, can survive in water, and has a longer lifespan. Waterbugs have 2 pairs of antennas while cockroaches only have 1. Water bugs also have a stinger that they use to kill their prey. Cockroaches on the other hand are good at hiding and can squeeze themselves into very tight spaces. Now that you know the difference, you can tell them apart the next time you see one!

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