Eucalyptus leaves are poisonous, but there are many kinds of eucalyptus, and koala only eats several kinds of eucalyptus leaves, and the leaves it eats are the less toxic part. Being koala's favorite is also forced. Many animals compete for limited food in the same environment, so koalas turn to eat leaves that other animals don't eat to maintain their own population.

rather than saying that eucalyptus leaves are koalas' favorite, it is better to explain that koalas can't grab other animals, so they have to choose eucalyptus leaves as their own food to survive. Its liver can decompose the toxins in the leaves and degrade the toxic eucalyptus leaves into non-toxic and delicious food to be absorbed. However, the little koala's ability to isolate toxins is not perfect, so the little koala can only eat its mother's excrement, and it will take more than one year to eat eucalyptus leaves by itself.

Eucalyptus leaves have little nutrition, so koalas have a very powerful digestive system to get the most nutrition from the leaves. Its cecum can even reach two meters, although humans or other animals also have cecum, but it is impossible to talk about it in front of this animal. There are many enzymes that digest and degrade cellulose in the cecum of koala, which enables koala to digest cellulose in leaves and provide energy for koala. But even so, the energy that can be obtained is still pitiful. So koalas almost only do one thing when they are awake, and that is to eat and keep eating.

koalas need a long time to sleep in order to isolate toxins and digest leaves. They can sleep for up to 18 hours, which allows their bodies to concentrate on processing food. Moreover, long sleep can also reduce energy consumption. After all, energy is hard to come by, and they have no extra energy to jump up and down. Koalas are also fragile creatures now, so we should cherish the environment and share our earth with other creatures.