The term "carnivorous plant," combined with memories of films such as "The Little Shop of Horrors," can lead to a flawed impression of Venus flytraps. The plant is capable of clamping its spiny leaves shut on helpless flies and actually digesting them. You might wonder if it could do the same thing to a human finger.
How the Trap Works
The trap portion of the Venus flytrap is made up of a modified stem and leaf blade, hinged together in a clam-shell-like shape. The inside of the trap is covered with fine trigger hairs. Disturbance of the hairs provokes a reaction from the plant. If a single hair senses touch, nothing will happen, as the trigger could be a raindrop or piece of dirt. If the hair is bumped twice, however, or multiple hairs are moved, the flytrap knows there's a live meal ready, and it snaps shut.
Your Finger in the Trap
If you stick your finger into a Venus flytrap, the trap will close. Nothing further will happen. Since the trap is really nothing but a leaf, you can easily pull your finger out again, and the trap will reopen slowly. Even if you kept your finger inside the trap, nothing would happen to it. It takes a Venus flytrap three to five days to digest even an insect.
Playing with the traps is strongly discouraged -- for the plant's safety, not yours. An individual trap can only close seven to 10 times over its lifespan, and every closing of the trap saps the flytrap's energy, especially when it's a false alarm. While an occasional demonstration is mostly harmless, continually springing the trap will eventually kill the plant, especially if it is in poor health to begin with.
Caring For Your Flytrap
Venus flytraps are hardy plants but only if cared for properly. The plant needs at least four hours of direct sunlight each day for optimum health and needs to be kept in a humid, cool environment. Normal potting and watering methods for other plant species are lethal for the flytrap. Keep the Venus flytrap in a pot at least 4 inches in diameter with soil that is equal parts peat moss and sand or perlite. Set the pot in a 1-inch dish of rainwater for proper moisture levels. During a dry spell, distilled water will substitute, but never give your flytrap tap water.