After the birth of a marsupial, the young comes out of the birth canal and into the pouch. From this stage the young develop for weeks or months depending on the animal. Inside the pouch the mothers mammary glands are located to feed their young milk. Wombats and koalas have pouches much different from a wallaby and kangaroo pouch. A kangaroo and wallaby pouch is in the front with an opening at the top. A wombat and koala pouch is towards the hind legs and is much tighter around the top to make sure their young don't fall out.