Pitcher plants have unusual tubular leaves that are shaped like urns, trumpets, or small pitchers. Insects are attracted to the mouth of the pitcher by nectar. The lip of the pitcher is covered with stiff, downward-pointing hairs that are not easy for an insect to climb upward on once it has partly gone down to gather nectar. Just below the lip, in the steepest part of the pitcher's throat, is a very smooth area without hairs. Like a greased slide, this sends the insect tumbling down into the liquid pool at the bottom of the pitcher, where it quickly drowns. The insect is then digested by enzymes inside the leaf.