How much do animals sleep?

We’ve all had that friend who constantly seems to be asleep. Call them at 10 about going to lunch? Haven’t even woken up yet. Call them at 6 PM about doing some that night? Taking a nap. Shoot them a text around 10 PM to see if they’re out for the night? Already gone to bed. And some people really do sleep quite a bit more than average, just like some sleep less; Thomas Edison was known to sleep less than 5 hours a night, regarding even that as “wasted” time. While most people need to sleep between 7 and 9 hours a night to perform at their best, it does vary from individual to individual.

But while people vary in how much sleep they need, we don’t even begin to compare to how wildly different species are in how much they need to sleep. If you think of sleepy animals, the first thing that comes to mind might be a sloth. I mean, just look at their name! And it’s true, sloths sleep about half the day every day. So does that 12 hours of sleep make them the reigning champ when it comes to sleep in the natural world? Oh no, it does not. Not even close in fact.

That title would belong to the brown bat. While populations vary in how much they sleep, many average as much as 20 hours a day! And to add a cherry on top, many of these nocturnal little guys also add in a stretch of hibernation during the colder winter months! So, they’re only awake 1/6th of the day, and even then for only about 8-9 months a year. Given a lifespan of less than 7 years, the brown bat may spend less than a single calendar year awake over the course of its lifetime!

On the flip side, there’s your common deer. Not only are deer awake throughout the day, but they are in fact most active in the early morning and late evening hours, leading them to sleep a yawn inducing 3 hours a night! While deers tend to sleep laying down, horses and giraffes not only sleep just as little (or perhaps even a little less) than deer...but they don’t even bother to lie down, instead opting to sleep standing. In fact, both horses and giraffes also tend to break up their sleep into smaller chunks, opting for a number of small power naps rather than a single extended snooze.

Yet when it comes to weird sleep, nobody can touch the walrus. These blubbery goons may look a little sloth-like, as if you’ve seen them they were probably lounging out and not doing much. And it’s true, while on land a walrus may sleep up to 19 hours at a time. Of course, you’d probably spend that much time asleep if you had stretches were you spent 3 to 3.5 days at a time swimming in the water without pause, as walruses do. Just to add a little extra weirdness on top, walruses don’t always sleep on land and spend their time in the water swimming...they’ve also been seen to take little 4-5 minutes naps underwater, or longer naps with their tusks anchoring them to a spot while the rest of their body floats.