A scene that looks like an icy alligator graveyard at first glance isn’t nearly as chilling as it seems.

In fact, a tableau of alligators partially frozen under the ice with their snouts sticking up into the air is evidence of the reptiles’ amazing abilities to survive.

Earlier this week, The Swamp Park in Ocean Isle Beach, North Carolina, posted a now-viral video on Facebook showing its alligators frozen in place in an icy pond. The park posted a similar video last year, which also went viral.

“18 American alligators are thinking ahead as they poke their noses up through the ice,” park manager George Howard can be heard saying in the video.

By Saturday, though, the alligators had thawed with the warming temperatures, Howard told HuffPost in a Facebook message.

“All thawed out,” he said. “Out of the water and in the sun today.” However, he added that with colder temperatures in the forecast, they may soon be frozen once again.

So how exactly are the animals managing to survive in such a bizarre state? The alligators themselves aren’t frozen solid, but are actually undergoing brumation, a process similar to hibernation.

“They basically shut down their metabolism,” University of North Florida biology professor Adam E. Rosenblatt told The Washington Post. “They don’t need to eat because they’re not burning a lot of energy. They slow down their heart rate, their digestive system, and they just sit there and wait out the cold weather. It’s a pretty amazing adaptation.”

They survive by sticking their snouts out of the ice, which allows them to breathe while keeping the rest of their bodies extended into deeper and warmer water, Inverse explains.

However, Howard told HuffPost last year that the gators could not stay in that state indefinitely.

“Obviously, that is not optimal, being frozen like that,” he said. “I can’t imagine it being very good for them if it was much over a week in cold water. That’s why you don’t see indigenous alligators north of North Carolina. Their bodies like the warmth.”