Have you ever wondered what Darth Vader would look like as an insect? A treehopper is probably a pretty safe bet. The foremost part of the thorax in this group of tree-dwelling insects is a hard protuberance in the shape of a horn, spine, bulb or crescent. It gives them the appearance of wearing a helmet or suit of armor. It also gives them a great deal of protection in the forest - these structures are tough enough to puncture skin or penetrate a shoe. With mouthparts modified for sucking tree sap, these insects are perfectly arboreal, a term that means living in trees, and rarely descend to the forest floor. They are called treehoppers for their habit of hopping away when approached or threatened.