Carnivorous plants are plants that feed on animals(insects). They engage in this type of feeding habit in order to obtain nitrates and these types of plants are commonly found in areas deficient in nitrates. There are well over 400 known species of carnivorous plants which usually trap and feed on small animals, most especially insects as earlier mentioned. Examples of these carnivorous or sometimes called insectivorous plants are butterwort, bladderwort, pitcher plant and Venus fly-trap and sundew.
The sundew and butterwort dwell in heaths and moors while the bladderwort dwell in ponds and ditches. Most of the carnivorous plants are tropical or sub-tropical plants such as the Venus fly-trap and the pitcher plants and all have green leaves and they obtain their carbohydrate through photosynthesis and obtain nitrogen from the bodies of the insects they consume.
Insects are usually attracted to these plants by scent, color or even sugary baits. They are then trapped and killed and then digested by a fluid that is rich in proteolytic enzyme and the amino acids released are absorbed by the plants. The features that make it possible for carnivorous plants to trap insects include--- sticky leaves as found in butterwort, a large sac as found in bladderwort, and adhesive hairs as found in sundew. The Venus fly-trap has in-folding leaves laced with spikes along the free edges and also a hinge-like midrib. When an unfortunate insect perches on a leave of the Venus fly-trap, the two halves of the leaves spring together and the spikes interlock so that the insect is trapped without any room for escape. Pitcher plants have pitcher shaped leaves which contain a digestive fluid. The nectar is the bait that attracts the insects to the lips of the pitcher, and as the insect tries to reach this nectar that is secreted near the brim, the insect then slips and falls into the digestive fluid where it is killed and digested.