Handbook of Insect Biology

Insects are numerous usually small arthropod animals of the class Insect having an adult stage characterized by three pairs of legs and a body segmented into head thorax and abdomen and usually having two pairs of wings. Insects include the flies crickets mosquitoes beetles butterflies and bees. Like other arthropods an insect has a hard other covering or exoskeleton a segmented body and jointed legs. Adult insects typically have wings and are the only flying invertebrates. The body of the typical adult insect is divided into three distinct parts the head thorax and abdomen.