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.

If you have children, or ever interact with them, the chances are you have heard them ask about whether or not fish sleep. On the surface, this seems like a very simple question, but trying to give ...

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 ...

Tom has a Master's degree in Journalism. His editorial work covers anything from archaeology and the environment to technology and culture. Tom has a Master's degree in Journalism. His editorial work ...

Do fish with no eyelids sleep? Given that they spend their entire lives submerged in water, this is a reasonable question to ask. Do fish with no eyelids sleep? Given that they spend their entire ...

Frigatebirds snooze in flight while penguins take four-second catnaps Emperor penguin chicks stand together in Antarctica. Penguin parents take thousands of catnaps a day while looking after their ...