Koala Bears Articles Behavior Characteristics Conservation Diet Habitat: Koala Bears Behavior. Arboricole (lives in the trees), rarely goes on the ground. They are completely harmless, and they adore the human lap, but be careful with their nails, they are very sharp. Koalas aren’t very active. They spend most of the day sleeping in the trees. When a sleepy koala moves, it often looks as if.