Antennae, or Feelers, jointed sense organs located on the heads of centipedes, millipedes, crustaceans, and certain insects. Crustaceans typically have two pairs of antennae; insects have one pair.
Antennae serve many functions. In most insects they are organs of touch, taste, smell, and hearing. In some water beetles they act as respiratory organs; in certain crustaceans they are used for locomotion. In many social insects antennae serve as organs of communication.
Insect antennae vary in length and shape from species to species, and sometimes according to sex. The antennae of some insects are longer than the body, those of others are short bristles. Insect antennae may be threadlike, beadlike, elbowed, saw-toothed, feathery, or club-shaped.