Koalas breed in the summer. The koala cub stays in the mother's pouch for 5 months. The koala cub is blind when it's born. The koala is very small when it's just born. After a month the cub is 1 cm. long. The koala weighs 15 to 30 pounds. One cub is born at a time. They are warm-blooded and their youngs are born alive. Koalas drink milk from the mother
The koala leaves the pouch first at about 5.5 months, permanently at about 8 months. The young koala then clings to its mother's back or stomach, sticking its head into the pouch to feed. During childhood, the baby koala eats partially digested eucalyptus that merges from mother's cloaca, thus receiving bacteria needed for digestion as well as food.