Here's why:
* Development: Kangaroo joeys are born very underdeveloped and rely on their mother's pouch for warmth, nourishment, and protection until they are strong enough to venture out on their own.
* Safety: The pouch is a safe haven for the joey, protecting it from predators and harsh environments.
* Nourishment: The mother kangaroo provides milk through teats located inside the pouch.
* Comfort: The pouch is a warm, snug space where the joey can rest and grow.
So, while kangaroos might have some other things in their pouches occasionally (like a little bit of grass or dirt), their primary purpose is to nurture and protect their young.