The Oriental cockroach known as the "water bug," is more closely associated with damp areas than the other common roaches. These insects feed on garbage and decaying organic matter and are often considered the filthiest of the house-infesting roaches. They are found in damp basements, cellars, crawl spaces, near drains, leaky water pipes and beneath refrigerators, sinks and washing machines, under floors, and inside walls. They forage mostly on the ground floors of buildings.

American cockroaches are reddish brown and have a yellowish margin on the body region behind the head. They are usually around 1 and 1/2 inches long. When disturbed, they may run rapidly and adults may fly. Immature cockroaches resemble adults except that they are wingless.

Adult German cockroaches are light brown except for a shield behind the head which is marked with two dark stripes. They are about 5/8 inch long. Young roaches are wingless and nearly black with a single light stripe running down the middle of the back. Egg capsules are light tan.