German vs American Cockroaches

German vs American Cockroaches

Two cockroaches account for most of the calls we take, and they could hardly be more different. Knowing which one you have tells you where it came from, where the population lives and what kind of treatment will actually work.

Start with size. A German cockroach is small, about half an inch long as an adult, and light brown or tan. Look for two dark stripes running lengthwise on the shield behind the head. Young ones are smaller and darker, with a single pale stripe down the back. An American cockroach is big, often an inch and a half long, reddish brown, with a pale yellowish band around the edge of the same shield. If the cockroach looks large enough to make you step back, it is not a German cockroach.

Next, location. German cockroaches live indoors in warm, tight spaces near food and water. You find them in kitchens and bathrooms, behind the refrigerator, inside appliance housings, in cabinet hinges and around the sink plumbing. Seeing several small ones, or seeing them in daylight, points to an established population. American cockroaches come from outside and below. They live in sewers, drains, damp crawl spaces and basements, and they wander in one or two at a time through drains, pipe gaps and vents. You are more likely to see one in a bathroom or basement than in a kitchen cabinet.

Behavior separates them too. German cockroaches breed fast and rarely fly. A female carries an egg case holding thirty or more young, and a small problem can become a large one in a couple of months. American cockroaches breed slowly, live for a year or more and can fly short distances, which is why one on the ceiling causes such a stir.

The treatment differs because the biology does. A German cockroach population lives in your kitchen, so the work goes to the harborage. A light problem is treated with bait alone, which the cockroaches carry back and share. A severe infestation gets a HEPA vacuum cleanout to remove live insects, egg cases and debris, followed by a liquid application. An American cockroach population lives in the ground and the drains, so the work goes to the routes. We advise you to fix water leaks first, then apply a general spray inside the home, underneath it and around the exterior. Bait alone does little for a species that is passing through, and a general spray does little for one hiding inside a dishwasher.

If you are not sure, catch one in a jar or take a clear photo next to a coin for scale. The inspection is free, carries no obligation, and settles it.