THE HEAD, EYES, AND MOUTH PARTS
The head is globular, usually a little flattened from front to rear. Two large compound eyes are located at the sides of the head, and the face or front consists largely of a plate called the clypeus. Above the clypeus and between the eyes are the antennae or feelers, which are believed to be the organs of hearing, smell, and touch. Below the clypeus is the labrum or upper lip, and the rudimentary mandibles; just below these are the two maxillae, which unite to form a tube called the proboscis, used in sucking nectar out of flowers. When not in use the proboscis is coiled up like a watch-spring between the two three-jointed labial palpi. The labium or lower lip is very small in butterflies.