By now, you’ve probably already seen the disturbing video of a seemingly reanimated fish carcass that’s been making the rounds on the web.

In a scene that appears to have come straight out of a zombie flick, a fish that’s already been cut in half and had its head removed begins flopping and thrashing around. It’s pretty distressing to watch, especially if you’re under the impression that it’s still alive. But don’t worry, folks — if you’re already horrified, rest assured that the fish is, in fact, dead.

The fish’s brain is no longer functioning, but its muscle tissues are still alive and can respond to stimuli such as table salt or soy sauce. When these make contact with the adenosine triphosphate in the muscles of a recently deceased fish, it can cause a chemical reaction that stimulates contractions, as you’ll see below.

Nature is fuckin’ crazy pic.twitter.com/i9NMO9tt0N

— Barstool Sports (@barstoolsports) July 11, 2017

(via IFL Science)

Even knowing the scientific explanation behind the movements, they’re still pretty creepy to watch. Imagine ordering a fillet only to receive it still dancing on the plate!