The largest land mammal, the wild elephant, sleeps just two to three hours a day in total, mostly in the form of short naps while standing up.
Certain land snails can sleep for up to three years in hibernation or estivation.
To Sleep or Not to Sleep
The tallest animal on earth, giraffes, have often been touted as the mammal that sleeps least of all, despite weighing up to 3,000 pounds. One commonly cited statistic estimates they sleep only 30 minutes per day.
Wild elephants average just 2 hours of sleep a night, making them the lightest-known snoozers of any mammal. Previous studies have looked at such habits in captive elephants, which sleep for 3 to 7 hours a day. But with more dangers and pressure to find food, wild animals tend to sleep less.
No animal can sleep for 300 years.
The correct answer is that they rest throughout the day. They rest lightly throughout their active months, but when hibernation season comes around, they dive in deep waters to sleep, that is.
Octopuses have blue blood, three hearts and a doughnut-shaped brain. But these aren't even the most unusual things about them! Known for their otherworldly look and remarkable intelligence, octopuses continue to reveal astonishing qualities, abilities and behaviour.
Koalas. Hats off to the (somewhat disputed) king of sleep: the Koala bear. They've been reported to sleep up to 22 hours a day in captivity, over 90% of their lives. In the Australian wild, that figure may be closer to 14.5 hours of sleep daily, boosted by 5 additional hours of rest and inactivity.
Different mammals sleep different amounts. Some, such as bats, sleep 18–20 hours per day, while others, including giraffes, sleep only 3–4 hours per day.
Cows. On average, dairy cows sleep for four hours each day. This sleep occurs in short bursts of three to five minutes. In total, cows spend about three hours in non-REM sleep, and 30 to 45 minutes in REM sleep per day.
Giraffes. Like elephants, giraffes often snooze while standing by locking their legs in place for sporadic power naps that are only a few minutes long. All in all, these add up to a mere four and a half hours of sleep per day.
Sloth. When people think of the word “lazy”, sloths are often one of the first animals to come to mind, and it's not surprising. They sleep for up to 20 hours a day and are known for being extremely slow-moving.
Sharks can sleep, and often opt to keep their eyes open while they do, according to new research published in Biology Letters. Because some sharks must swim constantly to keep oxygen-rich water flowing over their gills, it has long been rumored that they don't snooze at all.
Giraffes Only Sleep For Five Minutes At A Time.
Spiders usually have eight eyes but few have good eyesight.
Some spiders have median eyes that can detect polarised light and they use this ability to navigate while hunting.
While it can vary quite a bit, most snakes tend to spend much of their time asleep. The most commonly cited figure is 16 hours a day, though some species have been known to spend up to 22 hours!
The platypus (Ornithorhynchus anatinus) has a puzzling array of features. Not only does it have that iconic duck bill, it lays eggs like a bird or reptile but feeds milk to its young like a mammal.
Lithobates catesbeianus is an animal that cannot sleep.
Small bats, chipmunks and opossums all sleep for 15 hours or more per day. In contrast, big elephants, giraffes and horses all sleep for about five hours or less. Another factor is whether the animal is a hunter or is hunted.
Here are the animals that need the least amount of sleep: Bullfrogs go without sleep for months at a time! Though they close their eyes and rest, they remain alert and will respond to painful stimuli and show changes in respiration.
Humans sleep less than any ape, monkey or lemur that scientists have studied. Chimps sleep around 9.5 hours out of every 24. Cotton-top tamarins sleep around 13. Three-striped night monkeys are technically nocturnal, though really, they're hardly ever awake — they sleep for 17 hours a day.
Horses, zebras and elephants sleep standing up. Cows can too, but mostly choose to lie down. Some birds also sleep standing up. Flamingos live on caustic salt flats, where there's nowhere they can sit down.
Three-toed sloths are some of the slowest and seemingly laziest creatures in the world. Instead of evolving to eat more, they evolved to do less.
The American Pygmy Shrew (Sorex hoyi)
Every day it eats three times its own weight. To do so it needs to constantly eat and never sleeps for more than a few minutes. An hour without food would mean certain death. But this high-octane life style takes its toll – the 5 cm long animals typically live barely a year.
Brown Bat/Sloths – 20 hours
Due to lack of food they also spend 6 months of the year in hibernation. Sloths also spend 20 hours of their day asleep.