Science Minute Script:

Download Quicktime to listen to the audio clip.

Can Horses Sleep Standing Up?

This Science Minute was researched and written by Katie G. of Groton, NY.

Can horses sleep standing up? Yes!

When a horse is standing still, it's relaxed. A horse can remain upright for several days at a time. Its joints are locked in position by a system of muscles and ligaments. This system is known as the stay apparatus.

Horses can only lie down for a short time. When they lie down, their weight pushes against their hearts, lungs, and other organs.

So most of the time, horses sleep on their feet. But this can cause problems, too. Sometimes, their knees can get locked in place, and the animals won't be able to release them. In these cases, a simple operation is required.

In the wild, only some of the horses in a band will lie down. Others will remain standing to protect the group.