A Bug On A Twig Stock Photo

Insects (from Latin insectum) are pancrustacean hexapod invertebrates of the class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body (head, thorax and abdomen), three pairs of jointed legs, compound eyes and one pair of antennae. Their blood is not totally contained in vessels some circulates in an open cavity known as the haemocoel. Insects are the most diverse group of animals they include more than a million described species and represent more than half of all known living organisms.