A Koala bear takes a nap in the shade of a tree. A herbivorous marsupial native to Australia, these cute little fuzzy guys spend up to 20 hours a day sleeping. They spend just 15 minutes a day on any kind of social behavior. Eucalyptus leaves make up most of their diet and this also poses a risk to their survival. Eucalyptus trees are flammable and due to the Koala bear’s slow movement, they are vulnerable to bushfires in their native land. But on the plus side, there are many rehabilitation centers in Australia that care for this wonderful animal.