How do koalas normally act?

Some behaviours that koalas have are:

• When a male is marking his territory, he rubs his chest, which has a scent gland, on the tree bark
• Males have loud mating calls, which attract female koalas
• They tend to sleep 18-20 hours a day
• They eat eucalyptus leaves almost exclusively, although they also eat eucalyptus blossoms, and sometimes bark: the leaves provide nutrients and moisture for the koala
• Koalas have a home range of up to a square kilometre, consisting of many eucalyptus trees; consequently, they do not spend all their time in one tree, but often walk along the ground to change trees
• While they are solitary animals, their home ranges overlap, so that several koalas might share the same tree