Do you have a pet? A dog, a cat, a goldfish? If so, why? I don’t mean why did you adopt the dear things, I mean why do humans keep pets at all? It’s a strange behavior, when you think about it, and not one shared by any of our animal cousins. Jay Ingram is a top science writer and TV personality who’s spent decades exploring the natural world. His new book is called The Science of Pets, and he shares five of his key insights in the first half of the show. Then we hear from Marlene Zuk, author of Dancing Cockatoos and the Dead Man Test.