How long do koalas sleep each day?
Koalas sleep or rest for about 18 to 22 hours a day. Their diet of eucalyptus leaves is low in energy and hard to digest, so long periods of rest help them save energy.
Eucalyptus leaves are tough, fibrous and contain toxic compounds and little nutrition. Koalas have a long gut, including a caecum up to two metres long, where bacteria help break down the leaves. Digesting this food takes time and energy.
By resting for most of the day, koalas reduce the energy they need. They are mostly active at night and around dusk, when they feed, move between trees and call to one another.
Sleeping in trees
Koalas usually sleep wedged in the fork of a tree, with their thick fur cushioning them. On hot days, they hug cool tree trunks to lower their body temperature, a behaviour scientists recorded with thermal cameras.
Their fur is dense and water-resistant, acting like a raincoat in wet weather. Koalas rarely drink, getting most of their water from leaves, although they will drink during heatwaves and droughts.
Koalas are marsupials, not bears, despite the common nickname koala bear.
Did You Know?
A koala's fingerprints are so similar to human fingerprints that they can be hard to tell apart under a microscope.