Whether on a camping trip or somewhere closer to home, an encounter with a crocodile may just be anybody’s worst fear realized. You freeze and start to see your whole life flash before you, but, wait a minute, is that croc asleep? Whew!

But before you think you can rest easy and sneak past the beast, think again. Australian and German researchers have made an eye-opening discovery, literally.

It’s been known that birds, mammals like dolphins, and other reptiles have the ability to, in a way, “sleep with their eyes open.” Part of their brain stays awake while the other dozes off, allowing them to both sleep and be aware of their surroundings. And it looks like crocodiles aren’t any different.

“We had a human stand still next to the tank for 10 minutes – the animals responded to that quite strongly and watched the person closely with one eye,” said Dr John Lesku, who led the study. “After the human left the room they kept looking at the last location of the person with the other eye closed. This suggests that crocodiles have the same kinds of brain activity that birds do.”

Further research is still to be made regarding crocodiles’ brain activity while they are sleeping.