Why do koalas sleep so much?
Quick answer from Eartha
Koalas sleep up to twenty hours a day because their food gives them very little energy! They mostly eat eucalyptus leaves, which are tough, low in nutrients, and even a bit poisonous. Digesting these leaves takes lots of effort, so koalas rest and doze to save energy instead of running around all day.
The longer story
Eucalyptus leaves are not a very rich food. They are fibrous, hard to digest, and contain chemicals that would make many other animals sick. Koalas have a special long gut organ called a caecum that helps break the leaves down slowly.
Because this digestion takes so much effort and the leaves give back so little energy, koalas need to conserve every bit of power they have. Sleeping for eighteen to twenty hours a day is their way of balancing the books.
When koalas are awake, they move slowly and carefully for the same reason. Quick, energetic movements would burn fuel they simply cannot easily replace from their diet.
Koalas also get most of their water from the leaves themselves, which is why the word koala is sometimes linked to an old Aboriginal word thought to mean no drink, though koalas do drink water occasionally too.
Try this at home: slow-motion koala walk
- Pick a short path across the room.
- Move across it as slowly and gently as you can, like a sleepy koala saving energy.
- Talk about how it feels different from running, and why saving energy might help an animal.
Words to know
- Eucalyptus
- A type of Australian tree with tough leaves that koalas eat.
- Digest
- The way a body breaks down food to use for energy.
For grown-ups: what is my child learning here?
Age band: Ages 5-8
Curriculum link: Australian Curriculum v9 Science, Year 1 — living things have basic needs, including food and water, to survive.
The concept: Children learn that an animal's diet affects its behaviour, such as how much it needs to rest.
More classroom ideas are on our teachers page, and safety notes for families are on for parents.
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