Whether referred to as wild, feral, pigs, boars, swine or hogs, these adaptable animals are an invasive species steadily encroaching into over 35 U.S. states and several Canadian provinces. Brought to North America in the 1500s by settlers as a food source, these invaders used their high growth rate, early sexual maturity, strong fertility and adaptiveness to variable climates and habitat conditions to build their numbers to over 6 million in the U.S.