A team of researchers has revealed the secret behind how Venus flytraps determine whether prey wandered into its clutches or if a raindrop randomly fell on it.
According to BBC News, the carnivorous plants count the steps of flies that touch down on its trap. Two steps within 20 seconds of one another typically trigger the trap, but the researchers provided a bit more detail.
The new study is published in the journal Current Biology.
"The carnivorous plant Dionaea muscipula, also known as Venus flytrap, can count how often it has been touched by an insect visiting its capture organ in order to trap and consume the animal prey," study co-author Rainer Hedrich, of Universität Würzburg in Germany, said in a press release. "The number of action potentials informs [the plant] about the size and nutrient content of the struggling prey.
"This allows the Venus flytrap to balance the cost and benefit of hunting."
With tiny sensory hairs, the Venus flytrap automatically starts increasing hormones after detecting two steps and begins producing digestive enzymes after five once the prey is firmly in hand. To test the carnivorous plant, the researchers sacrificed a few crickets and used a specialized tool to test the Venus flytrap 60 times.
"For me, the interesting thing is that there needs to be something that tells the plant... to do certain things [after] a certain amount of touching," Rebecca Hilgenhof, a botanical horticulturalist who looks after carnivorous plants for Kew Gardens in London, told BBC News, "and a certain amount of time."