Nepenthes species are perennial herbaceous plants and frequently grow in very acidic soil, though some are epiphytes. All the species are carnivorous plants that capture insects and other prey by means of modified pitcher-shaped leaves that function as passive pitfall traps. Attracted by nectar secreted from the underside of the trap’s lid, the prey often slip from the mouth of the pitcher into a pool of liquid at the bottom and are unable to escape, because of the pitcher’s downward-pointing hairs and slick sides. The animals drown and are eventually digested by enzymes. 

Carnivory serves to supply nutrients, particularly nitrogen and phosphorus, in poor soil conditions. The flowers, which have no petals, are inconspicuous and produce minute seeds that are dispersed by wind.

One species, the endangered Attenborough’s Pitcher Plant (N. attenboroughii), is the largest carnivorous plant, reaching up to 1.5 metres tall. Its pitchers are 30 cm  in diameter and are able to capture and digest rodents and other small animals.