Females become sexually mature at about two years. After a short gestation period the female licks a trail of saliva from the pouch to the cloaca. The joey emerges and follows that trail up to the pouch, where the mammary glands are. After about 5 months it climbs out of the pouch and onto the mother's back, where it stays until it is about a year old. It makes the transition from milk to solid food by eating partially digested leaves from the mothers cecum.
Females bear one young every two years.
Females will also adopt abandoned babies. Their hind feet have a single opposable thumb. Koala means 'no drink' in Aborigine. They usually get all their water from eating leaves.