Q: Why can horses sleep standing up?
A: Horses can rest standing up but they can’t go into a deep sleep without lying down. They are able to rest while standing because they have a special set of supports (tendons and ligaments) in their legs that can be “locked” into a standing position. When a horse has “locked” his legs in place, his muscles don’t have to work as hard to keep him upright so he can rest safely. However, to go into a deep sleep, horses do still need to lie down and relax all of their muscles completely.
