How can horses sleep standing up but we can't?

Question

It would be impossible for us, but horses do it all the time. Most other animals don't stand up and sleep either. So why is this? And how is this?

Answer 1

Being a prey animal horses have developed a locking mechanism in their lags that keeps them standing if they fall asleep while standing.  This gives them an advantage of being able to awake and run away quickly if a predator/threat shows up.

Some other ungulates can do the same thing but I'm not sure which ones...

Other animals so not have this because it evolved sometime after the animals that have this adaptation branched off onto their own evolutionary pathway.  

Just to add:

Horses can and do sleep/doze standing up but  they do better if they have a safe comfy place to lie down down at night and get some Z's.

Most horses I have known prefer to lie down when they are tired and only remain standing if they do not feel safe.

Answer 2

because horses have 4 legs to balance on like a table. we only have 2 so we would tip over like a chair on 2 legs. horses have been know to fall over in their sleep too but it is rare

try it and let us know what happens

Answer 3

when a human goes to sleep, everything shutsdown except for your heart and lungs.

the same with horses. BUT they lock their legs so it looks like balanced like a table. unlike horses we'll just collapse.

Answer 4

Yes, horses do most of their sleeping standing up. Their legs can lock in place, enabling them to fall asleep without falling over. Because they are prey animals, horses often don't feel comfortable sleeping on the ground, and most of their sleeping is done during the day rather than at night when the predators are out hunting.

Horses have straight backs, so they cannot get up quickly. If a predator were to come while a horse was on the ground, they might not be able to get up fast enough to get away. However, horses do occasionally take short naps laying down during the day. This helps them to rest their legs. You can sometimes find a horse stretched out on its side, asleep in the sun, or laying on the ground with its legs folded under. When horses are in groups, they will often take turns 'gaurding' each other as they rest, with one horse standing up near the sleeping horse. This behavior would help to keep a wild horse from being attacked during a nap.

well hope this helps!

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