The episode should really be called "The One Where Rachel and Todd's heads exploded."
Science is wild and nature is crazy, get ready to have your mind blown by a recent discovery. This podcast covers female barklice genitalia and it's a doozy. In an effort to cut down on spoilers, we won't reveal much else about this topic in the show notes but pop over to our website for more info.
In This Insect, Females Have Penises And Males Have Vaginas. Ed Yong, National Geographic
Female Penis, Male Vagina, and Their Correlated Evolution in a Cave Insect. Kazunori Yoshizawa et al, Current Biology 2014