Animals and sleep

Just like human, most animals need sleep to function daily and live a healthy life. However, not all animals have the same sleeping pattern as humans- with some relying on little sleep, and others spending over half of their day sleeping.

Scientists are still unsure of a lot of facts when it comes to animals and sleep. Huge studies are still on-going on whether animals experience dreams just like humans. Although many studies prove that animals such as dogs may dream due to their movement during sleep, scientists are still not 100% certain.

Read on for more interesting sleep facts on how different species in the animal kingdom..


Dolphins sleep with half their brains turned off

The bottlenose dolphin uses only half of its brain and one eye during sleep. The other half of its brain stays awake, though at a much lower level of alertness. In this way, dolphins can watch for predators and rest while continuing to swim through the water.

Large dogs dream longer

Similar to humans, dogs go through several sleep cycles throughout their snooze sessions. Studies show that while small dogs dream more frequently, larger breeds dream for longer periods of time.


Ducks sleep with one eye open

Studies have shown that different sections of a duck’s brain sleep independently of each other. Even with just one side of the brain and one eye open, it only takes about a fifth of a second for a duck to be alerted to danger.


An octopus can change colour while they sleep

A video of an octopus named Heidi changing color while she slept went viral in 2019, prompting the world to ask: Do octopi dream? While most scientists agree that octopi do sleep, whether the color-changing is caused by dreaming or an involuntary neuromuscular behavior is still up for debate.


Orangutans make their own mattresses to sleep on

Unlike their baboon cousins, orangutans and other great apes sleep soundly on their backs. Great apes made the switch from sleeping on tree branches to constructing their own sleeping platforms millions of years ago, according to animal scientists.

Walruses can sleep practically anywhere

Not only can walruses go up to 84 hours without sleeping, but they also find some unique ways to crash when they finally get round to napping. Walruses can sleep at the bottom of an ocean floor or while bobbing on top of the water’s surface. These animals have even been observed sleeping while using their tusks to hang from a block of ice.

Some sharks constantly move while they sleep

Certain types of sharks must continuously move, even while they sleep to keep oxygen flowing through their gills. Some sharks get creative, resting in strategic areas on the ocean floor with strong currents to allow water to naturally flow over their gills.


Sloths sleep through about 80% of their lives

Sloths are known as one of the animal kingdom’s slowest and sleepiest animals. Though sloths sleep 15 to 20 hours every day while tucked high up in the trees, they typically remain motionless while awake, as well.

Cats can wake up immediately

Even though the life of a house cat greatly differs from that of its wild ancestors, domesticated cats have more in common with lions and tigers than you may realize. House cats still sleep for most of the day to save up their energy “for the hunt,” and can go from ffast asleep to fully operational almost instantly in the presence of danger.

Penguins sleep in groups and only for minutes at a time

To avoid becoming easy prey, penguins don’t let themselves fully fall asleep. Instead, they take short naps throughout the day, usually for just a few minutes at a time. Penguins prefer to sleep in large groups for added protection and warmth during the colder seasons.

Elephants sleep far less in the wild than in captivity

Studies of African elephants in 2017 found that the animals sleep significantly less in the wild than in captivity. elephants in nature only sleep for about two hours, while elephants in nature only sleep for about two hours, typically at night. What’s more, the elephants in the wild only entered REM sleep once every few days.


Migratory birds power nap while they fly

Some birds travel thousands of miles each year, often not stopping for days at a time. Scientists have found that these types of migratory birds naturally take thousands of micro-naps while in-flight during the day, with each lasting just a few seconds.