The Creature That Rips Its Own Face Open to Eat

Watch it happen.

Hydra eat by ripping apart their own skin, a mechanism that’s well known but had never been closely observed. Biophysicists at the University of California, San Diego, genetically engineered hydra to differentiate between their two tissue layers and better observe the feeding process. They found that a hydra’s cells contract to stretch apart, similar to how muscles in the iris of a human eye behave to open our pupils. But the researchers can’t account for why this nightmarish mechanism for feeding exists in the first place.