A large group of yellowfin tuna swimming off the coast of Italy. Like all fish, they sleep, but it's not like human sleep. Giordano Cipriani/The Image Bank via Getty Images From the goldfish in your ...

A protective mucous cocoon surrounds this parrotfish as it sleeps in Australia's Great Barrier Reef. This layer of protection helps fend off predators so parrotfish can get a good night's rest.

Researchers have discovered that some fish -- unlike humans -- do not need orexin to stay awake. This molecule was thought to be necessary for normal wake and sleep rhythms in vertebrates. Humans ...

You’re staring at your aquarium. It’s late. Everything is quiet. And there’s your fish, floating calmly, fins moving slowly, eyes wide open. Are they... asleep? Or just zoning out? Fish don’t come ...

Just like humans, Betta fish sleep at night. "When sleeping, they become still, with their eyes open because of their absence of eyelids. Betta fish may lose their color while sleeping (it's their ...

Sleep is one of the most essential parts of being human. Catching some Z’s is important for daily functioning. As adults, we've got to get in about eight hours a day, according to the Sleep Foundation ...

There are tens of thousands species of fish around the world, whether it's in an aquarium, river, lake, or ocean. Like all animals (and humans), every single one needs some form of rest for cognitive ...

One of the big, unsolved mysteries in science is exactly why humans and other animals sleep. There are plenty of hypotheses: it’s believed sleep is important in letting our organs repair themselves ...

Michael Heithaus does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond ...

Curious Kids is a series for children of all ages. If you have a question you’d like an expert to answer, send it to [email protected]. Could you explain how fish sleep? Do they drift ...