What animal sleeps the most?

All animals like to sleep, but some enjoy this revitalising activity more than others. 

Sleeping is a fundamental part of life for humans and is equally important for animals. While humans require a certain amount of sleep each night in order to function properly, for animals sleep is needed for a number of different reasons.

Sleeping gives the human body time to repair damaged damaged cells and restore depleted energy reserves. It is also crucial for mental well-being, along with processing and consolidating memories. Regular sufficient sleep helps to improve memory, retention of new information and skills, as well as concentration levels during our waking hours.

The amount of sleep needed by animals varies by species, but one thing we know for sure: some animals need a lot more sleep than humans. 

Sloths are famously known to be one of the slowest animals on the planet, so you might think they sleep the most but - this is not the case. 

Excluding hibernation periods, the animal that sleeps the most is the koala. They sleep a total of 22 hours each day. In the short time you’ll find a koala awake, they’ll be either eating or grooming.

The koala is not the only animal who sleeps a lot. Other top sleepers:

• Sloths that sleep about 20 hours per day

• Armadillos and opossums, known to sleep around 19 hours per day 

• Lemurs will sleep approximately 16 hours a day

• Hamsters and squirrels sleep around 14 hours per day

• Cats and pigs need around 13 hours of sleep per day

Dogs also sleep quite a number of hours per day, in total around 12-13 hours, but this is not continuous sleep. Dogs rest throughout the day by taking a number of day and night time naps.

In general, herbivores tend to sleep less than carnivores because they need to spend more time chewing to get enough energy from their food. This is especially true giraffes. In the 1970s, scientists discovered that that giraffes in the wild only sleep for between 5-30 minutes a day - due to their size, there’s a lot of chewing to be done!

Why do certain animals sleep so much?

There is no clear answer. For some animals, such as dogs, size seems to be an important factor. Larger breeds of dogs tend to sleep more than their smaller counterparts. 

According to the National Sleep Foundation, there may also be a correlation between brain size and sleep. Animals with large brains for their body size need significantly more REM (Rapid Eye Movement) sleep than others. The National Sleep Foundation also found that animals with a high metabolism, in relation to their body size, need less REM sleep than those with slower metabolisms.