Rhinoceros beetle (Golofa pizarro). All insects have six legs (three pairs), antennae and a segmented body (head, thorax and abdomen). Beetles, however have a hard carapace over their abdomen that supports and protects their bodies. The rhinoceros beetle feeds on nectar, plant sap and fruit. Males use their horns to fight other males in mating battles. The study of insects is called entomology.