Cockroaches are insect
Insects are a class of living creatures within the arthropods that have a chitinous exoskeleton, a three-part body , three pairs of jointed legs, compound eyes, and two antennae...

s of the order Blattaria or Blattodea, of which about 30 species out of 4,500 total are associated with human habitations. About four species are well known as pest
Pest (animal)
A pest is an animal which is detrimental to humans or human concerns. It is a loosely defined term, often overlapping with the related terms vermin, weeds, parasites and pathogens...


Among the best-known pest species are the American cockroach
American cockroach
The American cockroach , also known as the waterbug, or misidentified as the palmetto bug , is the largest species of common cockroach, and often considered a pest. None of the Periplaneta species are endemic to the Americas; despite the name, P...

, Periplaneta americana, which is about 30 millimetres (1.2 in) long, the German cockroach
German cockroach
The German cockroach is a small species of cockroach, measuring about to long; however, they are known to get bigger. It can be tan through brown to almost black, and has two dark parallel streaks running from the head to the base of the wings. Although it has wings, it is unable to sustain flight...

, Blattella germanica, about 15 millimetre (0.590551181102362 in) long, the Asian cockroach
Asian cockroach
Blattella asahinai, the Asian cockroach is a species of cockroach that was first described in 1981 from insects collected on Okinawa Island, Japan. It is nearly identical to the German cockroach except for a few minor morphological differences. Like the German cockroach, it is about long, is tan...

, Blattella asahinai, also about 15 millimetre (0.590551181102362 in) in length, and the Oriental cockroach
Oriental cockroach
The oriental cockroach is a large species of cockroach, measuring about in length at maturity. It is dark brown to black in colour and has a glossy body...

, Blatta orientalis, about 25 millimetre (0.984251968503937 in).