We have all heard that horses sleep standing up. That seems strange. Humans obviously sleep lying down, while other animals were familiar with like dogs, and cats also sleep lying down. The ability to sleep while standing seems like a strange and not very useful superpower. So what’s the truth?
Do horses sleep? Horses need to lie down for deep sleep, but they can also take short naps while standing. There are two reasons it seems like horses only sleep standing up. First, they nap on their feet a lot more than they sleep lying down. Second, horses sleep deeply at night. Since that’s the time humans also sleep, we are seldom around to see them asleep.
We are going to explain exactly how this works. We plan to also address a couple of other misconceptions about horses and their sleep habits.
Do Horses Sleep Standing Up?
Horses don’t sleep deeply while standing up, but they can doze that way. If that is the case, do they ever get any deep sleep?
REM Sleep
The kind of deep, dreaming sleep that horses and humans need to truly rest is called REM sleep. All the major muscles must relax during REM sleep. For this, the horse needs to lay down. However, horses only need about three hours of deep sleep each day. Horses save their REM sleep for nighttime. Unless you go out in the dark and look for it, you probably won’t see a horse in REM sleep.
Unlike humans, horses break their deep sleep into short segments. Instead of one long, three-hour rest, a horse will take five or six short periods of sleep that only last 15 or 20 minutes each. The horse must lay down for the short rests, but it will get back up when the deep sleep is over. Unless you check your horse frequently during the night, you probably miss this deep sleep.
Napping
Horses do take a lot of naps during the day. Depending on your horse, it may nap anywhere from 4 to 15 hours per day. These naps are not deep, refreshing sleeps; they are just quick cat naps, make that horse naps. These are the times that a horse rests on three legs. You can tell the horses dozing because its head will be low, and one leg will be lifted a bit off the ground.
While it naps, the horse’s eyes will be partially closed, and its lower lip will droop. The appearance is similar to a person who has dozed off while sitting up – everything is relaxed, and the posture is slack. It’s easy for a horse to wake up from this state and be ready for action.
How do Horses Stand while Sleeping?
Horses (and other large quadrupeds) have a special mechanism to let them rest on their feet. The mechanism that enables horses to rest standing up is called the stay apparatus. This mechanism is a combination of special ligaments and adaptations in the bone. The ligaments tighten and lock the bones into a rigid, vertical position. When the stay apparatus is engaged, the legs will hold the horse’s weight with no muscular effort. Since the horse can remain stable on three legs, the fourth leg can be lifted off the ground while it rests.
Horses will rotate which legs remain locked and which are rested throughout the day. This lets a horse rest each foot an equal amount during the day. When a horse is napping on three legs, it’s not in a deep sleep. Its eyelids will droop or even close, but it can wake up quickly. It’s not quite sleeping with the eyes open, but it’s close.
Horse Sleep Patterns
The sleep patterns of horses are shaped by the environment in which the species developed. Horses are prey animals–which means that much of their behavior centers on not being eaten by predators. Even though horses are now tame and live in protected environments, many of their responses are the same as they would be in the wild.
Since deep sleep is not conducive to escaping predators, most prey animals only need a little bit of deep sleep. From an evolutionary perspective, the horses that needed lots of sleep didn’t survive; it’s the light sleepers that got away from predators. That sleep pattern is also found in cattle and wild herbivores. Most grazing animals can sleep on their feet, as well. Horses aren’t the only species with a stay apparatus.
Team Napping
If you observe a herd of horses carefully, you will see that they rotate sleeping. Even in the middle of the night, some horses will lie down to sleep, but others will remain alert. When the sleeper wakes up, it will stand watch while the guard gets a chance to rest. Prey animals feel most comfortable sleeping in groups that allow some animals to rest while others remain on the lookout.
You can see similar behavior on warm, sunny days in the spring. In a group of horses, some will lie down to sun themselves while others remain standing. The horses will take turns lying and standing until every horse gets a turn to lay down. You may also notice that herd animals generally face in different directions while they graze or relax. That assures that the herd has eyes looking every way most of the time.
Stable Companions
Horses that are kept in a stable or other isolated environment have a hard time feeling comfortable when they rest. A horse should have another horse for companionship, or at least another equine. Donkeys and mules also make good friends for horses. Since the species are related, their behaviors and needs are similar.
Other animals also make good horse companions. Goats are frequent friends for horses. There are even some cases where a horse adopted a cat as a best friend! Whatever the companion looks like, your horse will be happier and sleep better with a friend.
Foals
Young horses – called foals – have a different sleep pattern. Like human babies, foals sleep a lot more than adults. New foals sleep about half the time, which is why it is common to see foals stretched out in the sun. Just like with humans, the amount of sleep needed by foals gradually decreases as they grow.
These are two other questions people have about horses and sleep. Besides the issue of standing versus lying down, some people believe that horses sleep with one eye open, or with one foot off the ground.
Do Horses Sleep with One Eye Open?
Horses don’t close their eyes all the way when napping on their feet, but they do when they fall deeply asleep. Napping is not quite the same as sleeping with one eye open, but it is close.
Do Horses Sleep with One Leg Up?
When they take standing naps, horses can keep one foot off the ground and remain stable on three feet. Since horses have four legs located at the corners of the body, standing on three legs makes a triangle. That’s how horses remain stable on three legs.
Conclusion
Horses have very different sleep habits than people. Instead of one long sleep each night, horses mix it up. They take lots of short naps while standing and a few deep periods of sleep while lying down. If you want to help your horse feel rested in the morning, make sure they have friends to sleep with at night so that they feel protected while they sleep.