We all know the feeling of hitting the snooze button on Monday mornings. Most of us need a solid 7 to 8 hours of sleep just to keep our brains and bodies from falling apart, but the animal kingdom plays by its own set of rules. You’ve got the African elephant doing perfectly fine in a mere two hours. But then, you have a creature that takes lounging to a next level. We’re talking about an animal that sleeps away almost its whole existence, racking up an unbelievable 18 to 20 hours of rest every day. That leaves them awake for barely 10% of their life!Let us find out which animal wins the trophy of heavy sleeper.

And the most sleepy animal is the Koala

People love to call them “koala bears,” but they aren’t bears at all. They’re marsupials, sharing a family tree with wombats and kangaroos. These fluffy Australian icons definitely take the prize for the sleepiest mammals on the planet. Snoozing all day is actually a hardcore evolutionary survival trick, completely driven by their incredibly specific and genuinely poisonous diet.

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Why do koalas sleep so much

A koala practically lives off eucalyptus leaves and nothing else. Out of the 600 or so eucalyptus species out there, koalas are picky, only munching on roughly 30 of them. Here’s why eating this specific foliage turns them into such heavy sleepers:Toxicity: To the vast majority of animals, eucalyptus leaves are deadly. They’re loaded with harsh chemicals like tannins and phenols. A koala’s liver essentially works double shifts to break down and filter out all that poison just to keep them alive.Low Nutrition: Not only the leaves are toxic, but they are also low on nutrients and calories.Massive Energy Drain: It takes a massive toll on the body to safely process toxins while breaking down dense, fibrous plant matter. This process drains almost all of their metabolic energy.Since they pull hardly any calories from their meals and burn so much energy just digesting it, koalas flat-out lack the fuel to move around. By sleeping up to 22 hours, they basically zero out the energy needed for movement. That leaves every ounce of their metabolic power available to tackle their brutal diet. Whenever they do manage to wake up for those quick two to four hours, they keep it simple: chew some leaves, or shuffle over to a different branch.

Who else is in the “Heavy Sleeper” Club

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The koala definitely wins first place, but a handful of other animals are not behind when it comes to racking up hours of sleep. Just like our marsupial friend, their extreme sleeping habits usually boil down to wild diets, super-fast metabolisms, or the strict need to conserve energy.Little Brown Bat: Taking to the skies burns a ton of calories. These bats save their fuel by sleeping up to 20 hours a day, frequently slipping into a deep, energy-saving state called torpor. They usually only rouse at dusk when the bugs are out and hunting is easiest.Opossum: Smaller mammals tend to have rapid metabolisms. Opossums burn through their fuel tanks quickly while scavenging in the dark, which means they need serious downtime hidden away safely in their dens to recover. Three-Toed Sloth: Sloths share a lot of similarities with koalas, surviving on a heavily fibrous, low-calorie leaf diet. Their digestion is absurdly slow. In fact, processing just one leaf can take up to a full month! To make it work, they have to sleep away the vast majority of the day which is around 15-20 hours just to keep their energy levels up.