Insects have two antennae, which are used for sensing their environment. The first antennae is known as a FEELER, which is a long, thin appendage that helps the insect detect vibrations and smells. The second antennae is known as a PALP, which is a short, thick appendage that helps the insect detect touch. Both antennae are important for the insect's survival, as they help it to find food, avoid predators, and navigate its environment.