Most of us may think that every living creature sleep normal like humans, but many studies done by sleep researchers discovered numerous and unique animal sleeping habits that differ from the sleeping habits of us humans. All animals have different sleeping habits; some sleep for a short period of time, some sleep for a long period of time, and some can do incredible things even while they’re sleeping. All the animals on this list have unusual sleeping habits that are interesting, and some are even incredible, too.
10. Walruses
Sleep researchers have defined the sleeping habit of walruses as a peculiar habit. A study reviewing the unique sleeping habits of walruses revealed odd and interesting discoveries of how these mammals sleep. In fact, walruses can doze off anywhere; both on land and in the ocean, but they also may shatter the world's record for constantly staying awake. In the ocean, walruses can sleep while floating at the surface, leaning, standing, and even lying at the bottom of the ocean. They can also sleep in the water while using their tusks to hang from ice floes. Another discovery indicated that walruses can also take a nap under water as they can hold their breath for 4-5 minutes. Yes, it's a very short nap, but the walruses do take these short naps on a regular basis. When they need more than a 5 minute nap, walruses inflate spaces inside their bodies, called pharyngeal pouches, with up to 13 gallons of air. These pouches allow them to remain under water while they're sleeping, making them bob up and down while keeping their heads above for air. On the shore, walruses can fall into a deep slumber that last for up to 19 hours! Scientists say this kind of intense sleep is needed, especially for the fact that the walruses can swim incessantly for almost 84 hours. Walruses also undergo "uni-hemispheric sleep" – sleeping with half their brain and the other half remaining alert. But as walruses swim the entire time in the water, this does not clarify the prolonged activity. Walruses can sleep and swim at the same time, too.
9. Porpoise
Porpoise are marine mammals and make up part of the cetacean species which includes dolphins and whales. They can dive deeper into the sea (over 650 ft), although they usually stay near or at the surface of the sea. Porpoises hunt for food and navigate the ocean using echolocation; even in complete darkness. There are six known species of porpoise, which includes the Harbor porpoise, finless porpoise, Spectacled porpoise, Dall's porpoise, Burmeister porpoise, and the Vaquita. A Dall's porpoise is known as the fastest species of all cetaceans as they were recorded swimming at the speed of 32 mph. What makes the sleeping habit of porpoises unusual is the fact that they swim slowly in circles while they are sleeping. This incredible sleeping habit of these marine mammals made researchers curious about how can they sleep while their body is constantly on the move. Just like dolphins, porpoises are extremely intelligent and are able to learn how to perform various tricks and complete specific tasks when taught by the trainer. Their incredible sleeping habit is the only remarkable trick that they have not been taught but have learned for themselves.
8. Grizzly bears
Grizzly bears are the subspecies of brown bears that inhabits the northwestern of the United States, Asia, Europe, and Scandinavia. Like most animals, they are adapted to survive the changing seasons. During summer and spring, they eat up large amounts of food so they can live off body fat during winter, when the food is scarce. They can intake over 40 kg of food a day, making them gain over 1kg of body weight a day. Grizzly bears hibernate more during the winter season, and their deep sleep allows them to conserve energy. Grizzlies certainly have unusual sleeping habits. Their heart rate slows down to 8 beats per minutes when asleep; when awake, their heart rate beats 40 times per minute. But this is not the only reason why grizzlies are included on this list. Another unusual thing about their sleep is that the pregnant female grizzly bears can give birth while sleeping. Yes, they go into labor while snoring! This means that the pregnant female grizzlies wake up to find that they have given birth to a new baby cub. If you're a woman who likes to have children but hate having labor pains, you might have a good reason to envy grizzly bears.
7. Dolphins and killer whales babies
Dolphins and killer whales have a different sleeping habit compared to other mammals. When they're still babies, they do not sleep at all for the first few months after birth, which means that they remain active 24-hours a day. You might think it's exhausting to be a mother if you're a dolphin or a killer whale, but they have learned to cope. It was discovered that the mothers have found a way to cope with sleep deprivation, facilitating rather than hindering a crucial phase of development for their offspring. All mammals that have been studied so far sleep the most as newborns, and others need less sleep as they grow to become adults. Adult dolphins and killer whales are known for their minimal sleep habits, but all cetaceans sleep with one eye open – also called a uni-hemispheric sleep. When cetaceans have their right eye closed, the left side of their brain is asleep, and vice-versa. This uni-hemispheric sleep is associated with slow, inactive brainwaves in the sleeping part of their brain. Keeping half of their brain awake allows them to be alert of danger from predators and helps to maintain their body temperature until they develop greater mass and blubber.
6. Migrating birds
It was shocking when scientists discovered that migrating birds fly nonstop for over 200 days (six months). They could only speculate that migrating birds do fly most of the year. The discovery was confirmed to be true when electronic monitors were attached to a half dozen of Alpine Swifts before they took flight for their migration. When the birds returned after six to seven months later, their data were downloaded and it appeared that the birds did not stop moving for over six months, and they did not even rest on the ground. This can make you curious about how did the birds eat and drink, but that too is also done during their flight. The birds feed on bugs, spiders and aerial plankton's that are swept into the sky by the high winds. Scientists believe they get much of their water from these prey. If these birds can fly nonstop for such a long time, the real question is, how do they sleep? Surely they can't stay awake for six months, but just like dolphins, they too can sleep with half their brain, but they usually take powernaps that last only for a few seconds. What makes their ways of hibernating even more unbelievable and incredible is the fact that they can still flap their wings by staying airborne even when they are sleeping. However, at night they can reduce flapping their wings by gliding for a long distance, but it's still unbelievable that they can flap their wings for such a long time. For us humans, you can just imagine how exhausting it would be to try walking for a few days without rest, or even sleeping while your body is constantly moving. This proves that migrating birds have more energy that can maintain them to stay airborne by flapping their wings for a very long time without being tired at all.
5. The American Black bears
Unlike other animals on this list, black bears do not sleep for a long time, neither can they sleep for the shortest time. In fact, it's not how they sleep that makes their sleeping habit incredible, it's what they're able to do even while they're asleep. When black bears are sleeping, their heart rates increase whenever intruders get close to them. This means that even when they are sleeping, they can tell when someone is coming. It's like their hearts have electronic devices that increase their detection beep sounds whenever something gets close. Even when you try to be quiet as possible when approaching a sleeping black bear, it will still wake up quickly to defend itself if you're a possible threat. This skill is indeed necessary as they cannot burrow below ground for protection. Black bears are active for up to 18 hours a day, and on an average their hearts beat 200 times a minute, rising to 250 when a human or a predator animal gets close to them during their sleep. For half of the year, bears are asleep. This is the time when they don't eat, drink, urinate, or defecate, and during this time their heart rate falls to as low as 14 beats per minute. Also, their metabolic rate falls to as much as three quarters when sleeping, and this shows that they are hibernating properly and not just in some form of prolonged sleep. If an American black bear fell asleep next to its food, it surely won't have to worry about other animals stealing it. It was also discovered that hibernating bears could also save lives of stroke and heart-attack victims.
4. Brown Bats
Bats are known for their weird and unusual sleeping habit of sleeping during the day and awake during the night. However, there is a species of "brown bats", which are different from the sleeping habits of other species of bats because they only stay awake for a very short time. In fact, brown bats sleep most of the time; they are only awake for 5-6 hours, meaning that they can sleep for 18-19 hours a day. Brown bats use three different kinds of roosts: day, night, and hibernation roosts.
3. Giraffes
Giraffes are usually known as the tallest animals, but there are more incredible facts about them. Like human fingerprint, each giraffe's coat is unique, especially with their patterns. Their coat colors also vary from white to light tan to nearly black, depending on what they eat and where they live. They have an 18 inch tongue that can reach around their hair-covered thorns called "ossicones". Giraffes have a sleeping habit that is unique from any other mammals because they don't sleep much like the others. Throughout the day, Giraffes only sleep for five minutes at a time, making it about 20-30 minutes a day. They sleep five minutes at a time because they are considered to be prey animals, so lying down to sleep will make it easier to get caught by predators. According to the University of Michigan Museum of Zoology, giraffes sleep standing, with one eye open and both ears moving. Giraffes can also go for a long time without drinking water because the acacia leaves that they eat contain a lot of water.
2. Koalas
Koalas are the only animals that you may think are born only to sleep. After scientists discovered that bats sleep for 19 hours per day, they thought they held a record for an animal that sleep for the longest time per day, but the koalas have proved them wrong. Koalas sleep for more than 20 hours a day! This means that they only have less than four active hours during which it they must use for doing other activities like eating, seeking and maintaining their territory, and also looking for potential mates. Koalas are also very lazy, so we cannot be totally surprised why they sleep for such a long time. Sleeping helps koalas to slow their metabolism.
1. The Land Snail
Most of us recognize the land snail as one of the slowest creatures on earth. Besides being garden raiders, some attributes of these creatures are very unusual and fascinating. Land snails have single hard shells – mostly coiled, which act up as shields and humidors. These hard shells are their only protection as they cannot escape or run away from predators. Their bodies are covered with a layer of mucus, which prevents them from drying out. Land Snails hibernate too, and they also need moisture to stay alive. When the dry seasons come, they use their developed trick to survive, which is an extremely long hibernation. When faced with a severe drought, snails can find a place to hibernate for up to three years! Some species of snails hibernate during the colder months of the year; so this means that they can sleep for the whole season without waking up. Other regular snails can stretch their sleep to a week, but most snails hibernate during dry seasons and wake up when the raining seasons have finally arrived. Unlike the migrating birds that take flight away from the drought seasons by flying nonstop for 6 months without enough sleep, snails just hibernate until the raining season come to moisture their living environment.
