The Gross Thing Baby Koalas Do That's Actually Essential To Their Development

When you think of baby koalas, you probably picture an adorable little joey riding on its mothers back or cuddling in her arms. What you probably don't picture is that same baby eating its mothers poop. According to Caroline Monroe, Wild Life Sydney Zoo's main koala keeper, the fact that baby koalas eat their mother's poo isn't a myth (via Nine). While it may incredibly sound disgusting, it turns out that this gross habit is an essential part of a koala baby's development.

As gross as it is, baby koalas don't just eat their mother's poop for fun. This facet of their diet is actually an important part of their young gut microbiome. In humans, we acquire gut bacteria essential for processing certain foods immediately after birth, according to the American Museum of Natural History. Koalas need gut bacteria for processing their diet as well, but require a little extra help (via BBC One).

The idea of eating poop may already sound disgusting, and unfortunately it's more gross than it sounds. As koala keeper Caroline Monroe puts it, "it can look really disgusting because the joeys use their mouth to stimulate the mother's cloaca [posterior orifice] to produce the pap, and it's quite wet. It gets everywhere" (via Nine). 

This substance, known as pap, is not like normal poop. It is much, much runnier. The pap is loaded with nutrients that the baby needs in order to grow (via PBS). According to the Australian Koala Foundation, pap acts like a transitionary food that koala joeys begin eating around six to seven months of age, between nursing and eating an adult koala diet. Since it does not require chewing, it acts similarly to the mushy baby food that we feed our own young before they are ready to try solid foods.

Baby koalas don't just use their mother's poop as an early food source. It turns out eating pap is essential for helping young koalas build their gut microbiomes. A koala's main food source is eucalyptus leaves, as well as the leaves of other related trees (via the Australian Department of Environment and Science). It turns out that eucalyptus leaves are fibrous and hard to digest, requiring specific gut bacteria, according to PBS.

Because pap comes directly from a mother koala's digestive system, it is full of her gut bacteria. Without eating pap, baby koalas would never be able to gain the gut bacteria needed to digest eucalyptus leaves, thereby allowing the animals to thrive off an otherwise toxic food source. In order to help koalas who have lost their mothers, some organizations feed them pap collected from other adult female koalas (via Nine).