Insects are numerous usually small arthropod animals of the class Insecta, 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 ...