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The Difference Between a Waterbug & a Cockroach

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Waterbugs and cockroaches look similar, and they are often referred to interchangeably. However, quite a few differences set them apart, including diet, habitat, biting habits and chance of infestation. Knowing the difference will help you determine which creepy crawler you're dealing with, so you can determine the best extermination protocols.


'Waterbug' is actually a broad term used to refer to several different kinds of bugs within the insect order Hemiptera. One of the most common is the giant waterbug, known as an alligator tick, toe biter or electric light bug. There are also several species of cockroaches incorrectly referred to as waterbugs, including the reddish-brown American cockroach and the shiny black oriental cockroach. These are often referred to as waterbugs because they gravitate towards sewers or damp areas.

Habitat and Food

As their name suggests, waterbugs live in water, at least most of the time. Cockroaches, although adaptable and able to live in a variety of habitats, are not aquatic like waterbugs. Another difference between the two is their diet. Cockroaches are opportunistic scavengers, dining on any available food source, including decaying or fermented food. This can include your garbage. Waterbugs, however, are more likely to hunt and kill insects, small fish, tadpoles and minnows.

Appearance and Bite Risk

Cockroaches and waterbugs both have flat, oval-shaped bodies. Regarding size, waterbugs average about 2 inches in length, and cockroach size varies by species. German cockroaches, for example, are about 1/2 inch long, while American cockroaches average about 1 1/2 inches long. Bite-wise, there are no confirmed reports of cockroaches biting people, but waterbugs sometimes do. The bites can be painful, and the process is creepy -- waterbugs inject digestive juice into the body, and then extract liquified tissue.

Extermination Methods

Although waterbugs bite, it's usually only when their environment is invaded. Cockroaches are more likely to create a nuisance by infesting homes and other areas. Extermination methods are similar in some ways. However waterbug control focuses more on reducing unnecessary water sources to deter these aquatic creatures. Cockroach control includes identifying the pests, using hygienic sanitation practices like removing garbage and dirty dishes, setting up traps or baits, and using insecticides. Beyond that, professional extermination may be necessary.