Female koalas bear only 1 koala a year. A newborn koala would only be about 2 centimeters long. A baby koala is called a "joey". Once born, it crawls in the mother's pouch for 6-7 months and feeds only on milk. After 22 weeks, the "joey" is able to open their eyes.At one year old, they are able to eat eucalyptus leaves from the eucalyptus trees.