Burrabb cubs leave the pouch when their muscles have developed. Unlike human babies who spend a couple of years being pretty helpless and needing to be taken care of constantly Burrabb cubs are physically capable and active. They’re also not very bright. Burrabb brains take about 5 years to develop to a point where a Burrabb can begin to learn language and “civilized” behavior. Until that point they are also primarily quadrupeds.