These butterflies are called swallowtails because they have long "tails" on their hindwings which look a bit like the long, pointed tails of swallows (a type of bird).

Life Cycle: The larva (caterpillar) hatches from an egg and eats its egg shell. After that it eats leaves almost constantly. The newly-hatched larva is brown and white, and looks like bird droppings, but it turns green later. The caterpillar molts (loses its old skin) many times as it grows. The caterpillar is plump, smooth, and green with large yellow "eyespots" that have black "pupils." There is a yellow and black stripe where its "neck" should be. The larva lives in a nest that it makes high in the trees by folding a leaf over and securing it with silk. It grows to be up to about 2 inches (5 cm) long. Just before pupating, it sometimes turns brown. It then emerges as a fully-grown adult. Adult butterflies do not have jaws; they can only sip liquid nectar through a straw-like proboscis.