Have you ever heard someone refer to a koala as a "koala bear?" Well, koalas are mammals, and they have round, fuzzy ears and look cute and cuddly, like a teddy bear. But koalas are definitely not bears. They are marsupials, like kangaroos, wallabies, and wombats, giving birth to a tiny, undeveloped joey that makes its way to a pouch, where it grows for several months. Koalas look soft, but their fur feels like the coarse wool of a sheep. They are masters of the trees, with long, sharp claws that help them climb and a rounded shape that helps them perch securely in forked tree branches as they sleep—up to 22 hours a day! They only eat eucalyptus leaves, which is tough food that needs lots of time to digest.