The Koala is a marsupial. In a marsupial, the newborn baby develops in a pouch on the mother's abdomen. A female Koala has one baby a year. The tiny baby, called a "joey", looks rather like a pink jellybean. It is totally hairless, blind and has no ears. It climbs to the pouch and stays there for seven months, living off milk from its’ mother, slowly growing and developing eyes, ears, fur etc. At about 22 weeks, its' eyes open and it begins to peep out of the pouch. It then begins to feed on a substance called "pap" (rather like a human baby is fed "mushy" food). Pap is a rich source of protein and micro-organisms which are needed for the digestion of eucalyptus leaves. The joey eventually grows too big for the pouch and rides on its’ mother’s back or belly and will begin eating eucalyptus leaves when it is 1 year old.