An insect has two antennas. Attached to the head are the antennas. They are usually long and protrude into the air. These antennas are used as their senses. However, each function of the antenna may differ depending on the type of insect it is attached to. Some of these functions may include touch, sound through vibrations, smelling and tasting. Others include heat and the motion within the air.
Most insects have only one pair of antenna. However, others may have two pairs. The insects may also use their antennas for more complex functions. These may be to help the insect to swim in water. They may also use their antenna to mate. The first set of antenna would be considered to be the primary antennae.