Found only in North America, the luna moth starts out as a very hungry caterpillar. Newly hatched, this caterpillar constantly munches on the leaves of walnut, hickory, sweet gum, and paper birch trees. After about a month of filling up on these plants, the caterpillar builds a cocoon. The insect lives inside for about three weeks, then emerges as a moth.

The eye-catching critter is easily recognizable because of its wings. But that's not the luna moth’s only interesting feature. The insect doesn’t have a mouth or a digestive system. That's because it only lives for about a week after leaving the cocoon, and it doesn't ever eat.