Getting adequate sleep is crucial for good health and wellbeing. However, some animals take sleeping to the extreme, spending over 90% of their lives asleep! This begs the question – what animal is the sleepiest of them all?
The Sloth
One of the sleepiest animals is the sloth. Sloths are arboreal mammals that live in the tropical rainforests of Central and South America. There are two main species of sloth – the two-toed sloth and the three-toed sloth.
Sloths have an extremely slow metabolism and low muscle mass. This allows them to conserve energy by moving very slowly through the trees. In fact, sloths only climb down from the trees once a week to go to the bathroom! Their slow lifestyle means they don’t need much energy, allowing them to sleep for long periods.
So just how much do sloths sleep? Sloths sleep between 15-20 hours per day on average. That means they are sleeping around 70-80% of their lives! Here is a breakdown of how a sloth spends its day:
| Activity | Hours per day |
|---|---|
| Sleeping | 15-20 |
| Eating | 10 |
| Other activities | 1-2 |
As you can see, sleeping takes up the vast majority of a sloth’s day. They even sleep while hanging upside down from tree branches!
The Koala
Another extremely sleepy animal is the koala. Koalas are tree-dwelling marsupials endemic to Australia. They spend most of their lives high up in eucalyptus trees.
Koalas have a very slow metabolism and low-energy diet, since eucalyptus leaves provide little calories. Moving slowly helps them conserve energy. Their inactive lifestyle allows them to sleep deeply for many hours.
Koalas spend around 18-22 hours per day sleeping. This means they spend around 75-90% of their time asleep! Here is the daily schedule of a koala:
| Activity | Hours per day |
|---|---|
| Sleeping | 18-22 |
| Eating | 2-4 |
| Other activities | 1-2 |
Koalas need to sleep deeply to conserve their limited energy reserves. Their sleep habits allow them to survive on a low-calorie diet in the eucalyptus forests.
The Opossum
Opossums are marsupials found throughout North and South America. They are omnivorous animals that live in a variety of habitats.
Opossums spend an impressive 19 hours per day sleeping, amounting to 79% of their life. They tend to be most active at night and sleep during most daylight hours. Here is the daily schedule of the opossum:
| Activity | Hours per day |
|---|---|
| Sleeping | 19 |
| Foraging for food | 4 |
| Other activities | 1 |
Opossums need plenty of sleep to conserve energy as they forage for food. Their nocturnal nature also lends itself to daytime sleeping. Opossums will find dark, secluded dens to sleep in safely during daylight hours.
The Bat
Bats are the only mammals capable of true flight. There are over 1,200 species found on every continent except Antarctica.
Most bats are nocturnal or crepuscular, meaning they sleep during the day and are active at night or during twilight. Bats spend an average of 19-20 hours per day sleeping. This accounts for 79-83% of their daily lives.
Here are the average sleep habits of a bat:
| Activity | Hours per day |
|---|---|
| Sleeping | 19-20 |
| Feeding | 2-4 |
| Other activities | 1-2 |
Bats need lots of rest during daylight to recover from their energetic nighttime exploits. Roosting allows them to sleep safely in seclusion. Some bats even hibernate during colder months, sleeping for weeks or months at a time!
The Lemur
Lemurs are primates found only on the island of Madagascar. They are arboreal animals that live in tropical forests.
The lemur’s low-calorie leafy diet and small body size allow it to sleep deeply for long periods. Lemurs spend around 16-20 hours per day sleeping, totaling 67-83% of their life sleeping.
Here is how a lemur divides up its day:
| Activity | Hours per day |
|---|---|
| Sleeping | 16-20 |
| Foraging & feeding | 3-5 |
| Other activities | 1-2 |
Lemurs need to rest and digest between bouts of feeding on fruits, leaves, and insects. Huddling in tree hollows allows lemurs to sleep soundly and conserve energy in Madagascar’s tropical climate.
Other Sleepy Animals
In addition to the animals listed above, there are a few other notoriously sleepy creatures:
- Giant armadillos sleep up to 18.1 hours per day.
- Pythons sleep around 18 hours per day.
- House cats sleep for 12-16 hours on average.
- Ducks sleep with one eye open but still spend around 12 hours sleeping.
- Squirrels sleep up to 15 hours per day in their dens.
Why Do Animals Sleep So Much?
Clearly, many animals spend more time sleeping than humans do. But why do some creatures sleep up to 20 hours a day? Here are some reasons why animals sleep so deeply and for so long:
- Energy conservation – Sleeping requires far less energy than being awake and active. Sloths, koalas, and other slow-moving mammals conserve their limited energy stores by sleeping.
- Digestion – Sleep allows time for food to move through the digestive system. Lemurs need to rest while leaves and fruits are broken down.
- Recovery – Long sleep periods allow animals to heal and repair their bodies while inactive.
- Safety – Sleeping in dens or other sheltered spots keeps vulnerable animals like bats and opossums safe from predators.
- Climate adaptation – Some mammals hibernate or sleep deeply to conserve energy in harsh environments.
- Nocturnal lifestyle – Animals like bats that are awake at night sleep deeply during the day.
Do any animals sleep even more than sloths?
Sloths may sleep up to 20 hours a day, but they don’t quite take the award for most overall sleep. Here are a few champion sleeping animals that rival or even surpass sloths:
Bats
Some bat species like the hoary bat and the pallid bat sleep an astounding average of 20-22 hours per day. They hibernate in winter for up to 11 days straight when insect prey is scarce.
Pythons
After a big meal, pythons need time to digest their large prey. They can sleep up to 23 hours to allow their metabolism to work. Pythons can go months between meals thanks to these lengthy digestion naps.
Koalas
Koalas come close to sloths by sleeping around 22 hours per day. Their eucalyptus diet provides so little energy that extreme sleep is essential for koalas to operate on minimal calories.
Opossums
Opossums win the prize for longest single snooze session. They can sleep continuously for 48 hours if undisturbed! But on average, they sleep 19 hours per day.
Armadillos
Giant armadillos hold the record for most sleeping hours, averaging an incredible 18.1-20.9 hours of shut-eye per day. That’s nearly the entire day asleep!
Conclusion
So which animal spends a whopping 90% of its life sleeping? While many creatures sleep over 75% of the time, the giant armadillo takes the top spot by sleeping up to 20.9 hours per day. That’s nearly 87% of its life asleep! Other top sleeping animals include sloths, bats, pythons, koalas, and opossums.
These champion sleepers all have slow metabolisms and low-energy diets. Sleeping over 20 hours allows them to operate on minimal calories from food sources like leaves, insects, small prey, or fruit. Extreme sleep also provides safety, aids digestion, and allows recovery time for these unique mammals and reptiles.
The next time you are envious of a sleeping cat or dog, just imagine what life would be like if you had to sleep 20 hours a day like a sloth! While depriving humans of mental stimulation and social time, those extra hours in dreamland allow some amazing animals to thrive on limited resources.