In the newest show from the Freakonomics Radio Network, host Zachary Crockett explores the hidden side of the things around us. This week: One creature’s trash is another’s cash. (Or, how one man found profit in pee.)

A sneak peek at Bapu's new book, "Random Acts of Medicine," available now from Doubleday, and an announcement about the show.

Couples get divorced for all kinds of reasons. Is having kids one of them? Bapu talks about research that investigates what happens to parents who unexpectedly have twins. Plus, an announcement about the future of the show.