Week Magazine: Then consider the nutria, a huge, "semiaquatic" rodent that looks like a cross between a beaver and a sewer rat, but with bright orange incisors. Also know as swamp rats, nutria on average weigh between 15 and 22 pounds; in the U.S., they typically reside in swamps in the deep South where they can always be near water.
That could all change soon, according to the United States Geological Survey, as a population boom and rising temperatures are spurring the varmints to venture farther from their...