Kangaroos are famous for carrying their baby joeys in their pouches. Other marsupials—quokkas, wombats, wallabies, koalas, quolls, Tasmanian devils, and opossums, for example—also carry their young in this way.
Pouches are different amongst different marsupials, two kinds distinguishable (on the front or belly): opening towards the head and extending the cavity under the skin towards the tail (forward, or up) or opening towards the tail and extending towards the front legs (to the rear, backward or down).
Plus, some extra insight from Echidna Walkabout:
On a warm day, a large macropod joey swings around in an airy hammock-like pouch for most of the day. Legs, tail and ears spill out in all directions as joey snoozes. But everything changes when mum hops!
Suddenly, the airy hammock becomes a pressure bandage. Kangaroo mothers have powerful muscles around the pouch, which can tighten quickly or relax completely. If mum needs to hop fast to escape danger, she can’t have a big loose load on her undercarriage – so she tightens her pouch muscles and presses joey hard against her belly.
It makes sense – if you were holding a baby loosely in your arms and suddenly had to run, you’d do the same. Hold the precious cargo firmly.
Watch these related videos next: A tiny newborn kangaroo climbs into its mother’s pouch and Kangaroo Dundee and his baby kangaroos.