Carnivorous plants feed on insects and other small animals, in addition to producing food in their leaves by photosynthesis. The nutrients absorbed from trapped insects enable carnivorous plants to
thrive in acid, boggy soils that lack essential minerals, especially nitrates, where most other plants could not survive. All carnivorous plants have some leaves modified as traps; many use bright colors
and scented nectar to attract prey; and most use enzymes to digest the prey. There are three types of traps. Pitcher plants, such as the monkey cup and cobra lily, have leaves modified as pitcher-shaped pitfall traps, half-filled with water; once lured inside the mouth of the trap, insects lose their footing on the slippery surface, fall into the liquid, and either decompose or are digested. Venus fly traps use a spring-trap mechanism; when an insect touches trigger hairs on the inner surfaces of the leaves, the two lobes of the trap snap shut. Butterworts and sundews entangle prey by sticky droplets on the leaf surface, while the edges of the leaves slowly curl over to envelop and digest the prey.
