A frequently despised insect for sure, but who am I to judge:)
Cockroaches (or simply “roaches”) are insects of the order Blattaria. This name derives from the Latin word for “cockroach”, blatta.
There are about 4,000 species of cockroach, of which 30 species are associated with human habitations and about four species are well known as pests.
Among the best-known pest species are the American cockroach, Periplaneta americana, which is about 30 millimetres (1.2 in) long, the German cockroach, Blattella germanica, about 15 millimetres (½ in) long, the Asian cockroach, Blattella asahinai, also about 15 millimetres (½ in) in length, and the Oriental cockroach, Blatta orientalis, about 25 millimetres (1 in). 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.