While in the pouch they are permanently attached to the nipple and once the young have developed they leave the pouch and do not return. The kangaroo's pouch opens horizontally on the front of the body, and the joey must climb a relatively long way to reach it. Kangaroos and wallabies allow their young to live in the pouch well after they are physically capable of leaving, often keeping two different joeys in the pouch, one tiny and one fully developed.