The Light Eaters: How the Unseen World of Plant Intelligence Offers a New Understanding of Life on Earth

by Zoë Schlanger

As mentioned, Venus flytraps can count to five, and can store the memory of that counting at least as long as it takes to figure out if it has a fly in its maw or not. How it works is this: if two of the trigger hairs inside the flytrap’s trap are touched within twenty seconds of each other—a good indication that a living creature is moving around inside it—the trap snaps shut. But the flytrap keeps counting after it closes. If the trigger hairs are disturbed five times in quick succession—eliminating all doubt that it has caught a living, wriggling creature—the plant injects digestive juices into the trap, and the meat meal commences. Digestion takes many days, so it’s important to be sure. But if the trap is triggered twice, snaps shut, and the triggering stops, the trap will open again within one day. Clearly whatever is inside is too small to bother with, or not a living creature at all, but perhaps a bit of twig or stone—or, in the case of all the flytraps that have told us anything about their kind, the cold tip of a botanist’s probe. The flytrap corrects for its error.