Cockroaches (or simply "roaches") are insects of the order Blattodea. This name derives from the Latin word for "cockroach", blatta.Among the most well-known species are the American cockroach, Periplaneta americana, which is about 30 mm long, the German cockroach, Blattella germanica, about 15 mm long, the Asian cockroach, Blattella asahinai, also about 15 mm in length, and the Oriental cockroach, Blatta orientalis, about 25 mm. Tropical cockroaches are often much bigger, and extinct cockroach relatives such as the Carboniferous Archimylacris and the Permian Apthoroblattina were several times as large as these. Cockroaches are generally considered pests; however, only about 30 species (less than 1%) infest urban habitats.
