With a few exceptions, all creatures in the animal kingdom sleep in one fashion or another. While they may not have a bed and rising time, getting a full eight hours like us humans, many animals have their own habits and strategies for sleeping. While some (mostly predators) lie down and doze off when they're tired, other animals have developed habits that allow them to sleep while keeping them alive. These are some of the strangest ones.
Sea Otters Anchor Themselves
Potentially one of the cutest sleeping habits in the animal kingdom belongs to the sea otter. When sleeping, sea otters stay in the water in order to avoid land predators. However, to ensure that they don't float away from where they are, they wrap themselves in seaweed which acts as an anchor.
To top it all off, the otters hold hands to stay together, with sometimes up to 100 otters creating what adorably is known as an "otter raft."
Dolphins Never Fully Sleep
Unfortunately for dolphins, they have to consciously breathe, even while they are sleeping. In order to get some shut-eye, these water mammals shut down half of their brain at a time. They also sleep with one eye always open, which is called unihemispheric sleep.
Not only does this kind of sleep prevent them from downing, but it also allows them to keep on the lookout for predators and escape as fast as possible if needed.
Bears Are Excellent Sleepers
One way that bears get the majority of their sleep is through a process known as hibernation. This is when bears eat as much as they can, find a comfortable cave, and sleep through the winter to avoid starvation.
While hibernating, their heart rate slows, and they don't eat, drink, or seven relieve themselves to save energy. If a bear is pregnant, she will wake momentarily to give birth, go back to sleep, and the cubs will nurse on the sleeping mother until spring.
Desert Snails Spend Most Of Their Lives Sleeping
Typically, most desert snails are only active from around 5-7% of the year, estimated to be around 15 to 30 days. The rest of the time, they aestivate, which is a form of hibernation.
These snails are the most active just for a few days, but only after rainfall during the winter season from November to March. Incredibly, some dormant snails have been known to survive in museum collections for six years, only to wake up finally.
Ducks In A Row
When it's time to sleep, ducks in a group will form a row. Not only does this keep the ducks together, but it also provides a level of safety for them. Those in the middle will sleep comfortably with both eyes shut, while the ducks on the end sleep with one eye open.
Using unihemispheric sleep, they keep a lookout for any potential dangers. Even with half of their brain sleeping, the ducks on the end can react to stimuli in less than a fifth of a second.
Bats Prefer Things Upside Down
Unless you've been living under a rock, you know that bats sleep hanging upside down. While this may seem strange to us, it makes perfect sense for these nocturnal creatures.
Not only does it allow for them to sleep in high places, away from any danger, but to fly away as quickly as possible if needed. There's no concern of them falling either because their talons are so strong that it keeps them hanging almost effortlessly.
Meerkats Protect The Alpha
Meerkats live in societies that are dominated by alpha males and females. Their communities can contain up to 50 meerkats that all live together in underground burrows.
When they aren't sticking their heads out of the hole to check for predators and sleep, they pile on top of each other in what is known as a heap. However, what's unique, is that the Alpha sleeps in the middle of the heap, protected by all the other meerkats.
Albatross Snooze In The Air
Considering that these sea birds spend the majority of their lives in the air hunting for food, there isn't all that much time for them to sleep. So, they have evolved to be able to sleep while flying.
Although it may seem hazardous as they could end up going off-course or crashing into something, they have mastered what is known as dynamic soaring, which allows them to ride wind currents as they peacefully glide and sleep.
Horses Can Sleep Standing Up
To sleep for short periods of time, horses sleep standing up. This is because it is a prey animal, meaning that it has to start running as fast as possible to escape predators. So, sleeping standing up is just for a quick nap.
This is possible due to an adaptation in their musculoskeletal system that enables their limbs to lock into place when they lose consciousness. However, in order to achieve a deep rem sleep, these animals have to lay down.
Sperm Whales Sleep Vertically
It wasn't until 2008, that we gained a partial understanding of how sperm whales sleep when researchers stumbled upon a group bobbing vertically in the water.
Although it was assumed that these whales participated in unihemispheric sleep like other mammals, it was discovered that they engage in short periods of full sleep near the surface of the water. Today, it is still unknown if this is the only type of sleep that they get or if they have another form in deeper waters.
Giraffes Hardly Sleep
Despite being one of the biggest animals on the planet, giraffes forego sleep more than most. According to Animal Planet, these animals sleep for just 30 minutes a day in five-minute intervals.
It's likely this is out of necessity because they live in such predator-heavy locations and have to constantly worry about lions, cheetahs, leopards, and more. So, when they do sleep, it's either by resting their head on their back or sleeping standing up.
Sharks Need To Keep Moving
In order to receive oxygen through their gills, sharks have to keep moving. So, it's not that sharks don't ever sleep, but researchers have concluded that it's more of an "auto-pilot" mode that they go into rather than deep sleep.
Other theories on how sharks sleep include that some white sharks might face the underwater currents so water can move through their gills without the sharks having to make any effort, allowing for them to be idle for some time.
Walruses Have Built-In Life Vests
With the ability to sleep and swim simultaneously, walruses can sleep a lot, considering that they can swim continuously for 84 hours. When sleeping in the water, walruses have the ability to inflate what is known as pharyngeal pouches that keep them afloat.
Walruses can also sleep on land for up to 19 hours and can take short naps underwater for as long as they hold their breath which is around five minutes. Basically, they can sleep any time and any place.
Apes Make Their Own Beds
Unsurprisingly, for the most part, apes sleep like humans, with orangutans, gorillas, and chimpanzees all curling up like people do. Furthermore, they are known to find platforms or make platform beds in the trees where they can sleep high above the predators.
Researchers believe that apes' sleeping patterns and their ability to sleep comfortably and for long hours may have played a role in the evolutionary process, also making them one of the most intelligent species in their environment.
Frogs Get In Tune With The Weather
Like some other animals like bears, frogs also hibernate during the winter months, although they do things a little differently. They have what is described as an internal antifreeze that allows ice crystals to form in their body cavities, creating high concentrations of glucose to protect their internal organs from the cold.
In this state, the frog stops breathing, its heart beating, along with all other bodily functions. Then when it thaws in the spring, it comes back to life.
Elephants Are Sleep Deprived
Studies have shown that these magnificent beasts only sleep around two hours each day. Of course, they can't take the chance of being unaware for two hours, so they sleep in small increments in order to stay wary of the predators.
Although these animals will sometimes lay down to sleep for short periods of time, it is much more advantageous for them to sleep standing up in case they need to run away from something.
Cows Aren't All That Sleepy
Although it may seem like cows spend the majority of the day sleeping while standing up or eating. In actuality, cows only sleep for around four hours a day, which doesn't seem like much for an animal that spends the majority of its day grazing.
However, cows spend more than half of their lives lying down, which means only a fraction of that time is spent sleeping. When they do sleep, cows are also known to sleep standing up.
Koalas Aren't As Lazy As We Think
Researchers have encountered several problems when studying animal's sleeping patterns such as identifying between what is actually sleeping and what is resting. Initially, it was believed that the koalas studied in zoos were sleeping up to 22 hours a day!
It was later discovered that it was more like 14 hours, and the rest of the time was "resting." Koalas need this much sleep because their diet consists of eucalyptus, which takes a lot of energy and time to digest.
Sloths Can Hang If They Want To
Because they stand little to no chance against a predator, they essentially spend their entire lives in the trees. Solitary creatures, in captivity, some sloths have been known to sleep up to 20 hours a day, while those in the wild sleep for no more than 10.
When they do sleep, sloths typically like to curl up in the fork of a tree or even hang from a branch using their claws and dangle out of reach from predators.
Penguins Sleep For Minutes At A Time
On the lookout for countless predators, penguins hardly ever really sleep. Instead, they take short naps throughout the day that are usually only minutes at a time! For extra protection, they will sleep in groups known as a rookery, which also helps create warmth.
Because some penguins can be out on the ocean for nine months at a time, it's assumed that they can also catch small naps in the water after their last meal of the day.
