This isn’t because the little critters are lazy; their diet of eucalyptus leaves requires them to conserve a lot of energy. It’s a common misconception that the oil in eucalyptus leaves ‘drugs’ them, and the sleepy state is a result of being drunk. However, koalas need to sleep in order to digest and break down their food, ‘ which is tough, fibrous, low in nutrition and contains 4 toxins which take a long time to digest.
Koalas eat between 200 and 500 grams (7.1 to 17.6 ounces) of eucalyptus per day. Their specially developed digestive system enables them to extract nutrients and detoxify chemicals in the normally poisonous leaves. They also extract water from the leaves, which is why koalas don’t drink much.