- The Venus flytrap thrives in terrariums.Jupiterimages/Photos.com/Getty Images
Most of the time, insects eat plants; sometimes, plants eat insects. Carnivorous plants are those species that feed on living creatures as well as the more traditional plant diet of soil nutrients, water and sunlight. A terrarium with controlled humidity and soil conditions is a good environment for carnivorous plants. Water carnivorous plants with rainwater or distilled water. Hard, alkaline water destroys the acidic environment they require.
- Perhaps the most well-known of the carnivorous plants, the Venus flytrap uses a snap mechanism to trap insects. Sweet-smelling nectar and brightly-colored extensions on its leaves attract its prey, which lands on the leaves, triggering them to snap closed. The plant then secretes an enzyme that dissolves the insect's body. Venus flytraps prefer a humid environment, ample sunlight and very acidic soil. Sphagnum peat moss works well as a growing medium. The leaves of the plant turn red when they receive adequate sunlight. If you are growing them indoors, use fluorescent lights positioned closely over the terrarium to supplement natural sunlight. Don't forget to feed your Venus flytrap. In a closed terrarium environment, it cannot trap its own food.
- The sundew traps its prey with a sticky, glue-like substance excreted by tiny hairs along its leaves, resembling morning dew. Insects land on the leaves and become trapped, eventually being digested by the plant's enzymes. Sundew thrives in a closed, humid terrarium with a highly acidic growing medium, such as sphagnum peat moss. Mix in perlite or coarse sand to prevent compacting. Feed the plants two or three small insects each month. Do not substitute meat of any kind.
- The pitcher plant uses a pitfall trap to capture its prey. Sweet nectar attracts insects to its long, rolled leaves lined with slippery wax-covered hairs. Once an insect slips inside, it becomes coated with wax and cannot escape. Liquid in the cupped leaves drowns the insect, which is then digested by the plant's enzymes. To prevent the leaves from filling with water and washing out the insect, the plant has a small gap in its leaves that functions as an overflow spout. Pitcher plants grow well in peat moss mixed with fine orchid bark and vermiculite.
- Genlisea, also called a corkscrew plant, has two types of leaves: above ground is rounded green foliage, and underground are long, narrow white leaves that resemble and function as roots for this rootless plant. These subterranean leaves are hollow, spiral-shaped tubes lined with inward-facing hairs. This trap is sometimes called a lobster cage; prey can easily enter, but cannot exit again. The hairs direct prey to the plant's digestion area. Genlisea feeds on soil-borne protozoa in a terrarium, but are semi-aquatic in nature.