Elephants and rhinoceroses are popular zoo attractions. But for a long time, they’ve provided a service beyond entertainment and education. Many city zoos have sold animal manure as “Zoo Doo,” “ComPOOst,” “Elepoo,” or “Zoo Poopy Doo” to city composting programs, farmers, and even Bloomingdale’s and Macy’s. In this episode of Weirdest Thing, I dive into the stinky history of poop, every zoo’s least endangered resources. Excrement from herbivores, such as elephants, rhinos, camels, and giraffes make the best compost. Carnivore poop could contain diseases, and regulators ask managers to incinerate insect poop to prevent any concealed eggs from escaping the enclosures. Some zoos, however, employ rhinoceros beetles to roll other animal’s poop into easily packable balls. However they decide to sell and market the poop, zoos have turned what could be an annoying mess into useful fertilizer.