Here's a riddle for you, what is something that stays behind in an environment after an animal is long gone? The answer is... POOP! What if we could use poop to study animals that would otherwise be difficult to track down? Well, Dr. Sam Wasser does just that. This week on Radiobio, we talk with Dr. Wasser from the University of Washington about how he uses poop to better understand animal populations with implications from tracking poachers to tracking whales.