There aren’t many plants kids would name as their favorite. It’s probably a pretty short list that includes classics like roses, Christmas trees, and, of course, the perennial favorite: the Venus flytrap. It’s a natural wonder that looks like it was ripped straight out of a horror movie. It’s a plant that eats meat! It’s an absurd sentence. If it didn’t exist, the only place it would make sense to see it would be as the monster in a Sci-Fi (or SyFy) Channel movie in the early 2000s.

For as long as we’ve been fascinated by it, scientists haven’t fully understood how this little chlorophyll-packed carnivore manages to snap its jaws shut so quickly. Now, according to new research published in Science, a team led by physicists at France’s National Center for Scientific Research, or CNRS, thinks it has solved the mystery.

For a long time, researchers assumed that the mouth snapped shut thanks to basic hydraulic principles. Water will rapidly move through the leaf, causing one side to expand and forcing the trap shut.

Scientists Solved the Mystery of How Venus Flytraps Catch Their Prey

The team at CNRS found that water moves way too slowly through plant tissue to cause that quick of a snap. The researchers measured how quickly water moves through the flytrap and found that it would take anywhere between 30 and 150 seconds to redistribute enough fluid to trigger its trap. The trap takes only about a second to snap shut, and the entire process takes as little as one-tenth to two-tenths of a second.

So, if it’s not a hydraulic system, then how is it doing it? Well, when an insect touches the trap’s little trigger hairs inside the mouth, touching at least two of them in rapid succession, cells on the trap’s outer surface quickly soften, losing around 30 to 40 percent of their stiffness. That lets the outer layer expand more than the inner layer, creating an imbalance that forces the leaf to bend until it reaches a critical tipping point, automatically shutting it like it’s spring-loaded.

The researchers say this finding represents the fastest known change in plant cell wall mechanics ever observed… And it’s not necessarily exclusive to Venus flytraps. In fact, all plants use some form of this during their growth. The only difference is that the Venus flytrap applies it to its feeding process, turning an otherwise benign shifting of weight into a deadly predatory tool.