NOEL KING, HOST:
Good morning. I'm Noel King. A gorilla at the Philadelphia Zoo named Louis has a peculiar habit of walking upright on two legs. He was recently caught on video strolling around, and it is delightful. Even more delightful - zookeepers say the reason he walks upright - he does want to get his hands dirty. Louis is a bit of a clean freak. His keepers have tried to accommodate Louis, even bringing together a little bridge so he doesn't have to walk through mud puddles. It's MORNING EDITION. Transcript provided by NPR, Copyright NPR.