Admit It, Squirrels Are Just Tree Rats

Ben Dantzer had spent several frustrating days trying to capture a single squirrel when the epiphany arrived. Dantzer, a rodent researcher at the University of Michigan, was standing in the Canadian Yukon, scrutinizing the uncooperative squirrel, which was perched high in a spruce tree. Then, all of a sudden, he felt as though he was looking at an optical illusion: When he viewed the squirrel one way, he saw a squirrel; when he viewed it another way, he saw a rat. “I kind of think of squirrels as rats in costumes,” he told me. “Like with a fur coat and a dog’s nose.” It’s true: The two rodents do look remarkably alike. And yet, for all their similarities, they elicit wildly different reactions from humans. Squirrels—. Rats—. What