Insect

Insects are a class of living creatures within the arthropods that have a chitinous exoskeleton, a three-part body (head, thorax, and abdomen), three pairs of jointed legs, compound eyes, and two antennae. They are among the most diverse groups of animals on the planet, including more than a million described species and representing more than half of all known living organisms.

http://en.wikipedia.org/wiki/Insect