Animals - Animal types and traits - Horses - Mammals - Animal sleep - Animal anatomy
Why can horses sleep standing up?
Correct!
Horses have a special anatomical mechanism in their legs, the so-called passive holding apparatus. Tendons, ligaments and joint structures, among other things, work together so that the legs can carry a large part of the body weight without the muscles having to be constantly active. This allows horses to doze while standing and go through lighter sleep phases. This ability is extremely useful for a large escape animal. A standing horse can react and run faster in the event of possible danger than if it had to get up from the ground first. The holding device therefore enables longer periods of rest while standing with comparatively low energy consumption. However, horses do not only sleep standing up. To get enough REM sleep, a particularly deep sleep phase with strong muscle relaxation, horses need to lie down. If you don't have a safe opportunity to do this for a long time, REM sleep deficiency can occur. The well-known image of a horse seemingly sleeping peacefully while standing usually shows a lighter phase of sleep or rest. To ensure complete, healthy sleep, lying down is also part of a horse's normal behavior.
Horses can rest while standing, but need safe lying down phases to get sufficient REM sleep.
