Animals that sleep standing up

Elephants often sleep standing up, especially during short naps. They lie down for deep sleep but not for long periods due to their large size.

Elephants

Cows can doze off while standing, though they typically lie down for longer, deeper sleep.

Cows

Giraffes take short naps while standing to avoid being vulnerable to predators, but they do lie down for deeper sleep.

Giraffes

Horses have a unique locking mechanism in their legs called the "stay apparatus" that allows them to sleep while standing.

Horses

Flamingos sleep standing on one leg, balancing perfectly, which helps them conserve body heat.

Flamingos

Zebras often sleep standing up to stay alert to predators, using their herd for safety.

Zebras

Bison can sleep while standing, using their strong legs to lock into place.

Bison

Donkeys, like horses, have a stay apparatus that allows them to sleep standing up.

Donkeys