Cockroach Identification: German vs. American

Cockroaches are flat, fast-moving insects with long antennae and spiny legs. They hide in cracks during the day and come out at night to feed. Four species cause most cockroach problems in Illinois homes and businesses, and they need different treatments, so identifying the species is the first step.

• German cockroach: ½–⅝ inch long, light tan to brown, with two dark stripes running lengthwise behind the head. By far the most common indoor cockroach.
• American cockroach: the largest, at 1½–2 inches. Reddish-brown with a yellowish band behind the head.
• Oriental cockroach: about 1 inch long, shiny and dark brown to black. Often called a "water bug".
• Brown-banded cockroach: about ½ inch long, with two light bands across the wings and body.

Cockroaches eat almost anything: crumbs, grease, pet food, paper, glue and even soap. A German cockroach female carries an egg case holding 30–40 eggs until they're about to hatch, and the young mature in a couple of months. That's why a small German cockroach problem can turn into a large one so quickly.

Cockroaches aren't a sign of a dirty home. Even very clean homes get them. The most common ways they arrive are:

• Hitchhiking in grocery bags, cardboard boxes, used appliances and secondhand furniture. This is how German cockroaches usually arrive.
• Through shared walls and plumbing in apartment and condo buildings, moving between units along pipes and wiring.
• Up from sewers and drains, especially American and Oriental cockroaches.
• Through gaps around doors, foundations and utility lines.

German Cockroaches

The cockroach most often found in homes, apartments and restaurants. They like warm, humid spots close to food and water: behind refrigerators and stoves, under sinks, inside cabinets and in bathrooms. If you see small tan cockroaches in the kitchen, especially during the day, the infestation is probably well established.

American Cockroaches

Large cockroaches that live in sewers, steam tunnels and boiler rooms. They're more common in commercial buildings and large apartment buildings, and they usually get into homes through drains and basements.

Oriental Cockroaches

These prefer cool, damp places: basements, crawl spaces, floor drains and areas around leaking pipes, washing machines and water heaters. They're slower than other species and are often found near the ground.

Brown-Banded Cockroaches

Unlike other species, they prefer warm, dry places and are often found higher up: in upper cabinets, behind picture frames, and inside electronics and appliances.