Venus flytraps can't hurt you, even if you leave your fingers in there for a long time. But what if you were a particularly creative mafioso who needed to dispose of a body? Is there a particular circumstance in which they could digest human flesh? Well, the answer is...
Barry Rice runs the website The Carnivorous Plant FAQ and is the author of several books about carnivorous plant cultivation. Like most of us, he's looked at the bloodthirsty little things, looked at his own fingers, and wondered.
In the real world, flytraps are actually in a great deal of danger from humans. Even the humans who don't uproot them, trample them, or trigger them enough times that the plants fatally expend their energy can accidentally poison flytraps by giving them tap water or starving them of sunlight.
Even insects mostly win the battle against insectivorous plants. An insect is much more likely to chew through the plant than be caught in its trap. The wrong kinds of insects — like spiders and some ants — can kill a flytrap if they are trapped and eaten. But still — they're plants, but they eat flesh. Under the right conditions, would they eat ours?
Rice came down with a case of athlete's foot, which caused him to lose chunks of skin. Toe skin in hand, he decided to try a little experiment. He fed the trap the skin and triggered it to close. Flytraps stay shut for about a week to digest insects, their major source of nitrogen. It took a while for this trap to open up again.
Rice admits in his report on the experiment that he didn't expect the plant to have digested the skin — he doubted that its fairly weak digestive enzymes would be able to break the proteins down. To his surprise, the scrap of skin was almost gone, and what was left was a partially digested goo. The plant lived, although it was from then on given a diet of wholesome insects. So it seems — under very specialized circumstances — a venus flytrap might eat a person, if they were cut up and fed to it a gram or two of skin at a time.