You’ve probably heard that big animals like cows and horses sleep standing up – but when it comes to deep sleep, it’s just not true!

While cows can doze off and sleep lightly on their feet, when it comes to REM sleep, they lie down just like the rest of us. This is true not just of cows, but of most other large herbivores as well – horses, bison, rhino, and more.

While they may not be in a deep sleep while standing, anyone who’s ever attempted to get a little shut eye in a meeting or on a train or any other location that requires sitting or standing, you might be wondering just how they do it.

Amy Johnson, of the University of Pennsylvania School of Veterinary Medicine explains: “The legs of horses [and other animals] have what’s known as the ‘stay apparatus.’ Their limbs contain tendons and ligaments that allow the animal to remain standing with minimal muscular effort, and thus allow them to stand—and even doze—for long periods.”

It is theorized that this ability is evolutionary – designed to help potential prey keep an eye out for danger. Another evolutionary advantage? They only need about 4 hours of sleep a day, significantly less than humans.

Want to know more about cows? Send us your questions and we’ll answer them in future blog posts.