Do You Know How Horses Sleep?
The sleeping habits of horses are quite different than humans. Most human sleep is usually a long, single stretch—about eight hours in a 24-hour day. Horses doze for various periods during the day and have short bouts of deep sleep lying down in the middle of the night. Horse’s sleeping patterns change depending on their age.
Foals lie down for frequent naps and spend about half of their day sleeping until they are about three months old. As the foal gets older, the frequency of the naps becomes less, and they are more likely to stand rather than lie down. Adult horses spend more time dozing while standing up than in deep sleep lying down.
How the Adult Horse Sleeps
Mature horses most frequently rest in a standing position, but this does not provide deep, or REM, sleep. In order to fall into a true deep sleep, all skeletal muscles must be relaxed; this cannot happen when the horse is standing. However, when standing, horses will fall into a deep doze, but can wake up and become alert very quickly. This is a survival mechanism for horses, since they evolved as a prey species. But how can a horse snooze while standing? Horses have a unique anatomical mechanism in their hind legs called the stay apparatus. This allows a horse's knee cap to pop out of place and lock the hind limb in a standing position. Although it sounds painful, in horses, it's no problem at all. When dozing while standing, this stay apparatus will lock in place in only one hind leg; the other hind limb will be relaxed. Often, the horse appears to be leaning on one hip.