Koalas are marsupials native to Australia, spending most of their lives in eucalyptus trees. Despite their common nickname "koala bear," they are not bears at all. These tree-dwelling mammals have fingerprints nearly identical to human fingerprints, a rare trait among animals. Koalas sleep up to 22 hours a day to conserve energy, as their eucalyptus leaf diet is low in nutrition. They have a specialized digestive system that allows them to break down toxic eucalyptus leaves that would poison most other animals. A koala's closest living relative is the wombat. These solitary creatures communicate through vocalizations, with males producing loud bellowing calls during breeding season. Koalas have no tail and possess sharp claws perfectly adapted for gripping tree bark. Each koala has a unique nose pattern, much like human fingerprints.