When birds sit quietly on a branch for long periods during winter, they are not usually sleeping but conserving energy, ...

Humans do very little when we sleep. This might not seem like a big deal, until you look to the dolphins as they sleep and swim with the pod. Or fur seals, who can sleep while watching out for sharks.

Sleep looks peaceful on the outside, but inside the brain, it is anything but ...

Rescue birds always find a way of outdoing themselves when it comes to the cuteness factor. They're already impressive, showing off their extensive vocalizations and defying all logic by figuring out ...