Koalas are called marsupials, and not bears, because that is what they are - marsupials. They are not related to bears in any way; and bears are placental mammals, not marsupials. Like most (not all) marsupials, koalas have a pouch in which to keep their young. Most marsupials, including kangaroos, wallabies, possums, bandicoots and koalas, share this feature, but some marsupials such as the numbat have just a rudimentary flap of skin to protect the joeys. Like other marsupials, koala joeys are characterised by being extremely small and undeveloped at birth. At birth, they take a long, arduous journey from the birth canal, driven purely by instinct, grabbing hold of the mother marsupial's fur to reach the pouch. Upon reaching the pouch, they latch onto a teat which swells in their mouth to