Sleep is for some one of the most pleasant activities there is, after all, getting into a warm cozy bed and forgetting our troubles for about eight hours every night sounds like a very pleasant experience if you can manage it. But that applies to humans. In the animal kingdom sleep is a much more lax proposal and some creatures can sleep not just the night away, but almost their entire existence. If you have cats or dogs, you might be surprised at how much they sleep per day, on average about twelve hours, but there are other animals that are a lot less prone to waking up and the reason is what they eat.
For humans, sleep accomplishes very important tasks for your brain function. It helps process memories, retain information and even solve problems. It can also help us with repairing muscles and getting into better shape, but one thing that we do not do better is digestion. Sleeping slows it down and can help you absorb more nutrients, which in today’s society is about the last thing we want. In fact, it is not recommended to go to bed until at least two hours have passed since your last meal. But animals are different.
What animals need the most sleep and some of the reasons why
Animal’s reasons for needing sleep are as varied as humans, different resting metabolic rates, diets that are low in nutrition, biological makeup, etc.. But the variation between species can be quite jarring for those that have never thought about it. For example, the animal that sleeps the most hours a day is not a sloth despite their reputation, it is a Koala. Koalas sleep between eighteen to twenty two hours a day, and they do need that much time to live. Since their diet consists mainly of eucalyptus leaves, this can make them very nutrient deficient, but if they sleep while they digest the food and live a very sedentary lifestyle, their diet is enough to sustain them.
To little surprise, the next animal that sleeps the most during the day is indeed the sloth, as they have a very low metabolic rate, but as they also eat leaves (not eucalyptus, as sloths primarily live in South America and Central America) they need to conserve a lot of energy and thus also lead very sedentary lifestyles, aided by the fact that their movements are quite slow.
There are plenty of other animals that sleep for over twelve hours per day and although not all of them are due to diet (and these are without counting those animals that hibernate for months at a time). Some of the animals who sleep the most are:
- 18-22 hours: Koala
- 20 hours: Sloth
- 20 hours: Little Brown Bat
- 18 hours: Giant Armadillo
- 18 hours: Python
- 18 hours: North American Opossum
- 17 hours: Owl Monkey
- 16 hours: Tiger
- 15 hours: Tree Shrew
- 14 hours: Hamster
- 12-16 hours: Cat
- 12-14 hours: Dog
- 10 hours: Star-Nosed Mole
- 9-10 hours: Red Fox
- 9 hours: Chimpanzee
Of course, this list is quite incomplete, as there are many other animals that sleep for plenty of hours a day but hibernate for months out of the year so they are not being counted, or animals whose existence is not even on our radar due to their rarity or the environment they live in being inaccessible to humans. It is still fun to see if the animals that we think are the “laziest” truly are so and to investigate sometimes a bit more in depth some of the quirks of the animal kingdom, as there is so little that we know about so many species.