Tropical rainforests get more sunlight and rainfall than most other places, making them so fertile that they abound with different life forms. While a hectare of forest in the Appalachian Mountains might contain as many as 30 different species of life, a hectare of tropical rainforest might contain as many as 300, according to the Biology Department at Marietta College. It is this great diversity of life that makes tropical rainforests home to some of most interesting species in the world, such as carnivorous plants.
The Nepenthes, or "pitcher plants," are carnivorous plants found in rainforests in Borneo, Southeast Asia, the Philippines and many other places. They grow like vines and can climb more than 30 feet up the trunks of trees. The leaves of Nepenthes plants form themselves into a pitcher-like shape. The brim of the pitcher is waxy and slippery. It is also covered in nectar. Insects are attracted to the smell of the nectar and slip on the brim, falling into the pitcher. The bottom of the pitcher is filled with a liquid that the animals are trapped and digested in. While Nepenthes mostly capture and eat insects, large specimens have been known to trap and digest rats. Some Nepenthes even emit ultraviolet light of the same sort that flowers do, to attract more insects to them.
The butterwort, or Pinguicula, is another type of carnivorous plant found in tropical rainforests. It is also possibly one of the most beautiful, producing brightly coloured flowers. The butterwort's leaves are covered in greasy hairs that produce a substance that attracts and traps certain kinds of gnats, the plant's primary food source. Found in South America, some species are carnivorous only during the summer. During the winter, they sport different leaves and do not capture insects.
Although it is found all over the world, the bladderwort prefers the tropical rainforests of South America. Some species live on land, and some live in the water. Some live in canopies of wet moss. They are composed of a network of branching stems that produce thousands of tiny round bladders, like tiny green balloons. These bladders have a door opening inward. They squeeze out their internal moisture so that the insides of the bladders are at very low pressure relative to the outsides. When the hairs on the outside of the trap are touched, the door opens and the prey (insects, worms, tadpoles and fish fry) is sucked into the bladder, where it is digested.