Species and Distribution
Cockroaches are a diverse group of insects with some 4,000 species worldwide. Sixty-nine species are known to exist in the U.S., and fewer that 10 species regularly infest homes.

The most common are the ubiquitous German cockroach, Blatella germanica; species belonging to the genus Periplaneta (usually the American and Smoky-brown cockroaches, P. americana and fuliginosa, respectively); - the brown-banded cockroach, Supella longipalpa; and the Oriental cockroach, Blatta orientalis. The German and brown-banded cockroaches are found almost exclusively inside dwellings. The others are more commonly found out-of-doors and enter homes and multi-family dwellings from the outside.

Habitats
Cockroaches can be found anywhere in homes, but usually where food, water and shelter are abundant. Kitchens, cabinets, and appliances are primary living and breeding quarters for cockroaches. Large outdoor-living species may also aggregate at entries from the outside.