Cockroach or roach, is the name applied to members of the Blattidae, a family of orthopterous insects. Some species live in human dwellings and are among the most abundant and persistent of household pests. In addition to eating human food supplies, cockroaches will eat soap, paper, books, shoes and clothing, even attacking the eyelashes and fingernails of sleeping humans. Cockroaches have an amazing ability to survive. According to various reports a decapitated cockroach will run around for a week before it dies of thirst (alternatively, its heart will continue to beat for 30 hours); and a decapitated female will find a place to lay her eggs before dying. Cockroaches can sense poison via tiny hairs without ingesting it and will then avoid such poison for the rest of their lives. Their wings fold to allow them to hide in very small spaces and their tight shell retains moisture so they can survive for long periods without water. Conventional insecticides have little or no impact on the cockroach population.
The cockroach is fast and clever. It is nocturnally active, and a sudden room illumination may find the walls swarming with hundreds. The cockroach has had homage paid to it by Kafka in a story of that name and in the popular song 'La Cucaracha'.
There are four species of cockroach which plague humanity (and they or their ancestors have been in existence for 350 million years): the German cockroach Blatella germanica, which is found world-wide; the American cockroach; the Oriental cockroach Blatta orientalis; and the brown-banded cockroach.