The Secret Pocket Explained: Why do Koalas Have Pouches?

Koalas have a special way of caring for their young. Their pouches play an important part in raising their joeys, so let’s learn more about how a koala’s pouch works.

Nov 16, 2023byLisa Szymanski
the secret pocket explained why do koalas have pouches

Koala bears are Australia’s favorite marsupials, spending most of their time high up in eucalyptus trees feeding on the leaves. When koalas give birth, their babies enter a special pouch similar to the way a kangaroo raises its young. Compared to the abdominal pocket of a kangaroo, a koala’s pouch works a little differently. They have a back-to-front pocket that they use to support their vulnerable joeys. To learn more about koalas and their pouches, we cover a few interesting facts about these incredibly cute creatures.

Koalas Have Pouches to Raise Joeys

koala joey peeping out of pouch
Koala joey peeping out of the pouch.

A koala bear has one joey at a time, but it’s not unheard of for them to give birth to twins. Once the babies are born, they’re safely tucked into their mom’s pouch, where they will remain for at least 6 months. At 6-7 months, they emerge from their mother’s warm pockets. The joeys will be strong enough to hold onto their mom’s back or stomach as she moves about the treetops searching for leaves and bugs. A joey will cling to their mom for a year before they are equipped to take care of themselves. Only female koala bears have these pouches for the safekeeping of their babies.

The Difference: Koala Pouch and a Kangaroo Pouch

koala bear lying on its back in a tree
Koalas have upside-down pouches.

A kangaroo has a prominent pouch on their stomach, but the difference between their pouches and those of a koala is the direction. A kangaroo pouch has an opening at the top, and the joey sits inside as it eats, sleeps, and grows. The koala bear’s pouch is found at the lower end of their body and is actually upside down. The koala mom will control the opening of her pouch to keep her joey inside. Kangaroos and other marsupials don’t have to do any work to house their babies, but koalas must actively close their pouches to keep joeys inside.

Koalas Use Their Sphincter Muscle to Manage Their Pouches

koala baby clinging to the back of the mom
Older baby koalas will live outside of the pouch.

With an upside-down pouch, the koala needs to prevent their joey from falling out. Amazingly, they have a sphincter muscle that they use to open and close this pocket. When the mother bear climbs trees or evades threats, she will close the top of the pouch to keep the baby inside. Marsupials such as possums and kangaroos all have muscles that will close their pockets to keep their young snug and protected from the cold. They do not use these muscles to hold their babies inside their pouches. Koalas will hold their joeys inside these pockets to keep them warm and prevent them from becoming easy targets for predators.

Joeys Feed Inside the Pouch

female koala holding her joey
Koalas are loving and protective mothers.

Every mother koala bear has two teats inside her pouch. The baby koalas that live inside these folds can easily access these teats for milk while remaining warm and protected. Joeys don’t feed on milk the entire time they’re living in their mom’s pocket. After around 6 months, the young marsupials become curious about the environment outside of the pouch and start peeking out. While their mom is feeding on eucalyptus leaves, the joey cannot consume vegetation right away and instead transitions to leaves by consuming “pap.” Pap is a sludge that is similar to fecal matter and is excreted by the mother koala to activate the digestive system of the baby. This way, young koalas have an easier time transitioning from milk to eating eucalyptus leaves.

Female Koalas Have Special Pouch Cleaners

koala joey inside pouch
Koala joey emerging from pouch.

The koala’s pouch faces outward and is located towards the sides of its body, which makes it nearly impossible for it to clean. They cannot use their paws to reach deep into the pouch. To prepare these soft pockets for the arrival of their joeys, they produce an antimicrobial liquid to sanitize them. The inside of a koala bear’s pouch is not lined with fur but with smooth skin. The release of the cleaning compounds will create a hygienic home for the arrival of their newborn. This process protects vulnerable joeys from exposure to bacteria and gives them the best possible start when they’re born.

Why a Marsupial’s Pouch Matters

close up of koala mother and her joey
Marsupials such as the koala use pouches to rais their young.

Koalas are called bears, but these fuzzy creatures are marsupials. All female marsupials have pouches on their stomachs that are meant to house their babies when they’re born. It is a safe place where the young koala joeys can live until they are bigger and stronger to cope with their natural environment. The only other marsupial to share a backward-facing pouch is the wombat which protects its young from exposure to sand as the adult burrows. A koala bear’s pouch is an important part of successfully raising their joeys. It has muscle control to keep their babies safely tucked away as they climb trees. Surprisingly, their pouches are not used to store food. They have little pockets in their cheeks that they use to hold their favorite food, eucalyptus leaves.

Lisa Szymanski
byLisa Szymanski

Lisa is a wildlife enthusiast who enjoys hiking and gardening and has four years of experience volunteering at pet shelters. She is the proud mom of two dogs, a Pitbull named Ragnar, a Boerboel named Blueberry, and four feisty chickens, or as she calls them, the \"queens of the yard,\" Goldie, Gray, Peaches, and Brownie.