No matter how sleepy they are, sometimes it’s just impossible to get the cubs to take a nap. And as all moms know, you just have to let them try to power through it. It’s the only way they’ll learn.

This is an archived article and the information in the article may be outdated. Please look at the time stamp on the story to see when it was last updated. You go to the zoo, and the animals are ...

This sleepy monkey is ready for a nap — and it shows! 🐒💤 With slow blinks, heavy yawns, and gentle slouches, he’s the definition of adorable exhaustion. Perfect for fans of sleepy animals, relaxing ...

It is well documented that sleep has a supportive effect on memory consolidation in animals. In fact, research has shown that specific types of memory consolidation, in humans, are linked to different ...

Sleepy prairie dog Poppy rests peacefully.