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Cockroaches Vs Water Bugs

There’s a lot of insects out there that it may be hard sometimes to make out which one you are seeing. Such is the case with some species of cockroaches like the Oriental Cockroach and the American cockroach which have often been nicknamed as waterbugs. This can be confusing because there are a class of insects that are actually (and correctly) called water bugs. In this article we will do our best to clear up the confusion and show you how to tell the difference between these similar looking pests that you may encounter in your home or yard.

What are Water Bugs?

Waterbugs refers to a class of insects that come from the Hemiptera order of bugs. There are quite a number of these pests such as the Giant water bug, water boatman, water scorpions. As their name indicates, these pests like to live and thrive in water. They are gifted with strong legs that they use as paddles to easily swim through water. Waterbugs can often be an issue when you have a swimming pool as they will travel from other areas to reside on a pool surface. For example, some water bugs such as water boatman have wings and can fly around. If they like your pool, they will fly down and make it their new home. Waterbugs are predators and eat mosquitoes, algae and other small pests to sustain themselves. Waterbugs have a painful bite and will bite humans if they get too close. They have even earned the nickname, “toe biters” because of their biting habits. Waterbugs also have an affinity for water and will gather around light sources which has earned them another nickname of “electric light bugs”.

Cockroaches That Are Mistaken To Be Waterbugs

The Oriental Cockroach is the cockroach that is often mistakenly called a water bug. It makes sense though because the Oriental Cockroach loves to frequent moist, damp areas. Oriental cockroaches are original from Africa, despite what their name states, and are recognizable by their shiny black or brown appearance. Oriental cockroaches are roughly about an inch long. Male Oriental cockroaches have wings while female oriental cockroaches are wingless. Despite the possession of wings though, Oriental cockroaches are unable to fly. The American Cockroach is another cockroach species that is mistakenly referred to as a water bug, again due to the pests tendency to frequent moist, warm and wet places such as sewers and drains. American Cockroaches are quite large, reaching nearly 2 inches long and are often reddish brown colored. An avid scavenger, American cockroaches will eat nearly anything that they can get their hands on and while they do have the potential of spreading germs and diseases because of the filthy, unsanitary areas they frequent, they do not directly harm humans because they don’t bite.

How To Tell The Difference Between A Cockroach and A Water Bug

While at first glance a cockroach and a water bug might look the same, upon further observation you will be able to tell distinct differences between the two to be able to tell them apart. Here we will discuss the various characteristics and tendencies that separate one from the other.

Recommended Read: What are the Different Types of Cockroaches?

Insect Size and Appearance

While Oriental Cockroaches and American Cockroaches are larger sized species of cockroaches they are usually much smaller than water bugs. At the most, these cockroach species range between 1 to 1.5 inches in length while most species of water bugs are 2 inches long. Some water bug species can even grow up to four inches long, which can be a startling sight to see. Oriental and American Cockroaches have the typical external shell that is either a shiny black or reddish brown while Waterbugs. They have 6 six legs and a pair of antennae. Water bugs have a much varied appearance coming in brown, greenish brown. Water boatman have legs that are longer and stronger than their other legs to help them move easily through water. Giant water bugs have a flat oval shaped body that is tan or brown, resembling a dying leaf. Water bugs can also be distinguished from cockroaches from their clawed front feet that allow them to easily snatch prey and their mouthparts that they use to pierce and suck the pray they have pounced on or to bite any enemies when they feel threatened. If you were to put these cockroaches and water bugs side by side, you will notice that they don’t look the same at all though they are both creepy looking brownish colored bugs.

Habitat and Behavior

Oriental and American Cockroaches may love water and need it to survive, they are not able to live in water, preferring to just be in close proximity to water. They need moisture and dampness and this is why they frequent sewer system, drainage pipes. This is often what gives these cockroaches access into a home as they will come up through drains and occupy areas that are dark, damp and secluded like basements, laundry rooms, garages and crawl spaces. Oriental and American Cockroaches do prefer to live outdoors though around dumpsters, yards that have a lot of leaf litter and mulch, around pieces of firewood and other such places. Most of the time that they venture on into a human dwelling is when the weather is cold and rainy and they are seeking a shelter to stay out of the conditions. Water bugs on the other hand are aquatic creatures, they need to live near or in water for their survival. These bugs are most often discovered in ponds and lakes but move so quickly that it can be hard to spot them. Water bugs can even go underwater and hold their breath for long periods of time as they go around hunting for prey to eat. They also lay eggs in the water and once hatched that larvae begin to go on a relentless hunt for food to aid its development. When it comes to behavior, cockroaches are generally more shy. They don't want to confront anyone and for the most part like to be left alone to do their scavenging without interruption. This may be why they are nocturnal and do most of their activity at night unbothered or why they inhabit areas that are secluded and there aren’t many visitors. If you turn the lights on and discover them, they are quick to try to scamper away and find a place to hide. Waterbugs on the other hand are much more aggressive. As predators, they are always on the hunt for their next meal. If you happen to come into contact with a waterbug, they will not hesitate to bite you if you get too close. The bite can be painful but thankfully it is not poisonous or hazardous to health.

Eating Habits

While cockroaches are scavenger insects that are not picky about what they eat, choosing to consume whatever they happen to find during their travels. Waterbugs are natural predators of the aquatic areas that they live in. Some of the smaller water bug species eat insects like wasps, mosquitoes and other such small pests, while the Giant water bug will actually hunt and eat larger prey like small fish and even frogs. Some water bugs will even try to eat animals that double them in size like snakes and baby turtles! The way they are able to do this is from their powerful limbs that they use to snatch and seize prey and their mouthparts which their use to pierce into the prey and injects them with their lethal saliva. The saliva basically turns the prey’s insides into much and then they suck the innards out like a straw to a milkshake. Waterbugs are definitely not a pest to mess with in water.

Pest Level

When it comes to being pests and annoyance to humans, Cockroaches are a far bigger problem than water bugs because they are much more likely to get into homes. Waterbugs can also often get into homes through much of the same ways that Oriental and American cockroaches get in (via drains and plumbing systems) but they won’t want to stick around because they want to live in water so venturing into a home is purely an accident. Cockroaches that venture into homes like the Oriental and American cockroach will choose to stick around and may even lay eggs and start to breed in the secluded areas where they hide. As long as there is water to nourish themselves and food to eat, they will continue to stay. To alleviate this problem and stop the infestation from growing, address moisture issues and eliminate food sources and these cockroaches will leave on their own. You can then keep them from returning with exclusion measures and application of cockroach repellent products.

Recommended Read: The Ultimate Cockroach Guide

As mentioned earlier, where water bugs can be a pest is if you own a swimming pool. If you are not regularly keeping it clean and free of algae, waterbugs will arrive and they will treat your pool like the ponds and lakes that they are used to. In such cases, you will need to clean out your pool and chlorinate it to kill any algae and once cleaned up, water bugs will leave on their own or you can help expedite the process but skimming them out of the water, making sure to be careful that you don’t get too close and risk getting bitten.


While water bugs is a name that gets thrown around quite loosely, we hope that the information in this article has helped to clarify what waterbugs really are and how they are different from cockroaches.