|The head has two large compound eyes, two long clubbed antennae, a proboscis and two labial palpi. The rounded compound eyes are composed of hundreds of tiny individually lensed eyes. Together, they render a single, somewhat pixelated color image. Adult butterflies have good vision and are able to distinguish light in both the visible and ultraviolet range. Above the eyes are two long and slender antennae that are clubbed at the tip. They bear various sensory structures that help with orientation and smell. At the front of the head, below the eyes, are two protruding, hairy, brushlike structures called labial palpi. They serve to house and protect the proboscis, or tongue. The proboscis is a long flexible straw-like structure used for drinking fluids. It can be held tightly coiled below the head or extended when feeding. The length of a butterfly's proboscis determines the types of flowers and other foods from which it may feed.