I think that the reason it is called a joey is because a kangaroo's baby is called a joey also. The koala and the kangaroo are related. The young are very playful. A koala eats only eucalyptus leaves, bark, and gum tree leaves. Baby koalas eat the same things as grown koalas do.
Some koalas have their own trees.
That is why they eat only one kind of leaves. Most koalas eat eucalyptus leaves so there are a lot of eucalyptus trees in Australia. Doing this project was a lot of fun. I really like koalas. This project has helped me a lot.