This is a re-broadcast of one of our most popular episodes of season 7, The Science of Butts!

What is a butt? That’s what science journalist Katherine Wu wanted to know. Her quest for an answer leads her into a web of big butt questions, and a search to find the top butt scientists in the world. She discovers a debate over where butts come from, and a very strange butt that could rewrite the annals of butt history.

This episode features an original song called, “Sometimes Butt.” Trust us, it’s a fun one! (And yes, we say the word “butt” and other butt-related words a lot.)

Can’t get enough of butt science? There’s plenty more! Listen to a bonus interview episode with Katherine Wu, available to Patrons who support Tumble at a level of $1 a month or more. You’ll get access to an ad-free feed with all our bonus episodes, at patreon.com/tumblepodcast

This episode is based on Katherine’s article, “The Body’s Most Embarrassing Organ is an Evolutionary Marvel.” Find more butt science resources on the blog on our website, sciencepodcastforkids.com.

Tumble en Español, our Spanish-language show, has new episodes starting January 27th! Check out that feed at here.