Insects are animals belonging to the class Hexapoda. They have a segmented body with three distinct regions; the head, the thorax, and the abdomen. The head bears one pair of antennae, compound eyes, and the mouthparts. The thorax bears three pairs of legs (one on each of the three thoracic segments). The thorax bears often one or two pairs of wings (on the second and/or third thoracic segments). A gonopore is present at the posterior end of the abdomen.