The plant’s leaves have evolved into a funnel, with a hood like structure growing over the opening to prevent rain water from diluting the digestive juices. Insects are attracted by colour, smell and a nectar-like secretion on the lip of the pitcher. Slippery footings, aided in at least one species, by a narcotic drug lacing the nectar, causes insects to fall inside where they die and are digested by proteases and other enzymes