Plants are static, they cannot 'stalk' their prey. Instead carnivorous plants lure it, trap it, digest it and absorb the nutrients as a sort of soup.
Prey is usually insects and other small invertebrates, but occasionally frogs, birds and small mammals may be caught by large tropical species.
There are four methods of trapping:
The Venus fly trap (Dionaea) has leaves like a man trap. Modified, toothed,
leaf tips with sensitive trigger-hairs, snap shut on prey
which is digested by enzymes secreted from glands on the
inside of the traps.
Sarracenia, Cephalotus, Darlingtonia and Nepenthes all use this method. Insects are attracted to the colours and sweet secretions inside the pitchers, but lose their footing on the smooth hairs and waxy surface, falling to the bottom of the pitcher where they are digested, either by plant enzymes or by bacteria.
Sticky surfaces are used by the sundews (Drosera) and the butterworts
(Pinguicula). Insects are attracted to shiny glands covering the
leaves but become covered in sticky, dew-like secretions and cannot escape.
A trapping method used by Utricularia involves an underwater bladder with trapdoor entry. Tiny animals are sucked into the bladder in a rush of water as the trapdoor flies open.