Koala with Joey
© 1992 Christine Krieg
Koalas are a special kind of mammal. They are called marsupials. As such, they bear live young (except for the platypus which lays eggs). However, the young koala is still an embryo when born, no more than inch or so. It then burrows its way through the fur to the mother's pouch. As you can see, even when fully developed it doesn't leave the mother's pouch.