During the 1980s, Canadian farmers began breeding wild boars with their domesticated swine to create larger pigs that produced more meat. Over the years, some of the animals escaped from captivity. And when market demand for their meat slowed, many of the remaining hogs were set free. The farmers didn't think that the creatures would survive the bitter cold of Canada's winters ?" but they were horribly mistaken. Those boars' descendants have continued to multiply, and their numbers have exploded in recent years. The result is a population of "super pigs" with a tolerance for extreme cold and the capability to birth large litters.