Sleeping all day long, who is the "king of sleep" in the animal kingdom?

Produced by: Science Popularization China

Author: Li Zhen (Institute of Zoology, Chinese Academy of Sciences)

Producer: China Science Expo

Sleep can restore energy and relieve fatigue. Adequate sleep, a balanced diet and proper exercise are three health standards recognized by the international community.

In the animal kingdom, there are many animals that are particularly good at sleeping. They sleep much longer than humans. This article will give you an inventory of these animals that are good at sleeping.

Koalas are drowsy because of poisoning? You misunderstood them

Koalas only live in Australia, mainly live on eucalyptus trees and feed on eucalyptus leaves. They sleep for up to 20 hours a day. Many people believe that eucalyptus leaves contain toxins and koalas sleep for so long because they are poisoned, but this is not the case.

Koalas have an enzyme in their livers called cytochrome P540, which enables them to break down the toxins in the leaves, freeing them from any side effects of the toxins.

The reason they need to sleep for so long is that the energy content of eucalyptus leaves is so low that they can only digest the leaves effectively through sleep and get the nutrients and energy they need from this toxic food source. If they don't sleep for so long, the little energy they get from the leaves will be used up quickly, and they may become very weak and eventually die.

(Photo source: Veer Gallery)

So, don’t laugh at koalas for sleeping too much, it’s called surviving in bed!

Sloth: Who—are—you—calling—lazy?

Sloths are animals that live in South America. Due to the lack of sufficient energy sources and warm-keeping mechanisms, they need to reduce their metabolism to maintain body temperature. Therefore, their lifestyle is slow. They move, eat and sleep very slowly, with an average speed of only about 4 meters per minute, making them one of the slowest mammals in the world. When facing danger, sloths can run a little faster - up to 4.5 meters per minute.

Sloths in captivity typically sleep 15-20 hours a day, while wild sloths typically sleep 8-10 hours. While sloths don't sleep all day, that doesn't mean they're active either. In fact, they spend most of their waking hours completely inactive, often with their eyes closed. They like to sleep curled up in a ball in the fork of a tropical tree, or by hanging on to a branch by their paws.

(Photo source: Veer Gallery)

Leo: Sleep whenever you want, so willful!

Male lions sleep for nearly 20 hours. Female lions sleep 15 to 19 hours a day, less than male lions, because they have to take care of their cubs and hunt. Lions can even sleep for up to 24 hours after a full meal. This is because the environment in which lions live is very hot, and they often face the problem of water shortage, so they adopt this lazy lifestyle to reduce energy consumption. Especially when the dry season comes, prey is scarce and they are often hungry.

In addition, lions need to consume a lot of energy to hunt and protect their territory, so they need enough rest to restore their physical strength. When lions sleep, they usually choose some places with shade or shelter, such as shade, bushes or rocks.

(Photo source: Veer Gallery)

Lions also exhibit some behaviors similar to domestic cats when they sleep, such as snoring, yawning, or licking their fur. Lions are one of the most powerful and majestic predators on the African grasslands. Since they have no natural enemies and can always find water and shade to escape the heat, they can nap without worry.

Bat: I am the best sleeper among all flying animals

Bats spend nearly 20 hours sleeping every day, the most sleepy of all flying animals. They are one of the smallest mammals in the world and the only mammal that can fly. They hang in caves or branches to rest during the day and come out at night to look for insects, fruits, nectar, etc. Since flying consumes a lot of energy and oxygen, bats need to rest for a long time to replenish their energy.

(Photo source: Veer Gallery)

Armadillo: The Sleepy Lone Ranger

Armadillos sleep almost 80% of the day, about 20 hours. Armadillos have excellent hearing and a keen sense of smell, which help armadillos navigate at night. Armadillos can sniff out insects up to 6 inches below the earth's surface. They also use this keen sense of smell to locate potential threats and predators.

(Photo source: Veer Gallery)

Ball Python: Eat once a week, sleep once a week

Ball pythons are nocturnal and spend most of the day sleeping, napping 20 to 23 hours a day. When hunting, ball pythons swallow their prey whole, and this eating behavior means that it takes a long time for its digestive system to completely break down the food, and they are asleep during most of the process.

(Image source: az-animals)

House cat: Nothing to do? Then I'll take a nap.

Domestic cats need 12 to 20 hours of sleep a day, most of which is light sleep, and only a small part is deep sleep. Domestic cats will choose a comfortable, safe, and warm place to sleep, and sometimes change their sleeping position with the movement of the sun. Domestic cats will also show various postures and movements when sleeping, such as curling up, stretching, snoring, etc.

(Photo source: Veer Gallery)

Dolphin: Half of my brain is sleeping, but I am actually always awake

Dolphins are a general term for animals of the family Delphinidae in the order Cetacea, and they are mainly distributed in the world's oceans and rivers. The two hemispheres of a dolphin's brain can take turns to rest, ensuring that at least half of the dolphin's brain is awake to adapt to its life in the water and its need to regularly float to the surface to breathe air. In other words, dolphins "don't need sleep." But on average, dolphins spend about 8 hours a day sleeping, and they are the one who sleeps the least among today's protagonists.

(Photo source: Veer Gallery)

Conclusion

In general, these animals that sleep a lot have many unique characteristics in terms of sleep, such as long sleep time and good sleep quality. This also reminds us, "Read more books and newspapers, eat less snacks and sleep more!" While pursuing efficient production, we should also pay attention to our own health. Proper sleep can improve physical health and work efficiency.

Editor: Sun Chenyu

References:

【1】az-animals.com

【2】animals.mom.com

【3】livescience.com

【4】Planck Institute for Ornithology

【5】Konadhode, RR, D. Pelluru and PJ Shiromani, Unihemispheric Sleep: An Enigma for Current Models of Sleep-Wake Regulation. Sleep, 2016. 39(3): p. 491-494.