Why do baby koalas eat their mothers’ poop?

Gut bacteria is essential for our health. The human body’s microbiome, the unique mix of bacteria in our bodies, can “break down food the body can’t digest, produce important nutrients, regulate the immune system, and protect against harmful germs,” among many other essential uses.

Koalas also rely on gut bacteria in their digestive tracts, except baby koalas require a rather surprising kickstarter to get their microbiome up and running. After nursing for six months, they’re ready to try some solid foods. And they start with pap feeding. Tumble Science explains…

Koala shocker! …Basically, they nuzzle at their mom’s butts until she excretes a big, sloppy poop. (That’s a technical term! No just kidding.) It’s not poop, it’s pap! This is like a transition between milk and those tough, toxic leaves.

See it to believe it.

And from this Microbe Minute by science journalist Ed Yong:

The tannins in eucalyptus keep the leaves from being digested, but the koala’s gut is packed with bacteria that unlock the nutrients.

The babies aren’t born with these microbes. They get them from their mother. She excretes sludgy stuff called “pap.” It’s a kind of baby food packed with the bacteria the joeys will need after they’re weaned.

There’s a lot of information here, but don’t miss this surprising fact: There are 800 species of eucalyptus. Learn more about koalas in the Tumble Science podcast below.

Watch these videos next:
• How the food you eat affects your gut
• You Are Your Microbes
• Baby Koala: A Joey moves in its pouch at the Taipei Zoo
• Baby Koala Elsa at Australian Reptile Park

Bonus: Poop videos, including Kids Meet A Poop Doctor and why aren’t bird nests covered in poop?