The animal kingdom is full of fascinating adaptations, and one of the most intriguing is the ability to sleep with one eye open. While humans drift into deep slumber with both eyes closed, several ...

This story was originally published by CalMatters. Sign up for their newsletters. If you’re serving hard time inside a California prison, you’ll often find yourself stuck in a cramped cell with a ...

Some animals do it for survival, while others have evolved this ability for different reasons. It might seem strange, but these animals have developed abilities to rest while staying alert to their ...

Have you heard the saying about “sleeping with one eye open”? It’s a bit of metaphoric advice about staying vigilant—and a way to describe very light restless sleep. But sleeping with eyes open is ...

Wading through a clear knee-deep tidal pool in coastal Florida, I was trying to move slowly, to avoid disturbing a gorgeous American oystercatcher napping on a small sandbar. Oystercatchers are ...

Sleep-deprived jackdaws spent more time in deep, symmetrical sleep – especially early in the night, when the need to recover is greatest. As most people who have pulled an all-nighter will agree, lost ...

If you're serving hard time inside a California prison, you'll often find yourself stuck in a cramped cell with a complete stranger. You hang a bedsheet to manufacture the semblance of privacy between ...