In the past three decades, wild pigs have been spreading across America like crazy—to the tune of 5 million of the porkers in 39 states. The pigs have been part of the landscape since the 1600s, when early settlers allowed them to roam; some escaped, though their numbers have long been relatively few and largely limited to the South. It's unclear what's behind the recent surge, but experts are working hard to find a way to contain them, Scientific American reports. Between the damage they cause and efforts to control them, wild pigs cost some $1.5 billion per year. In addition to eating crops, they can ruin fields by digging, threaten local species, and contaminate streams with their feces. "I've never seen any one species that can affect so many livelihoods and resources," says a Texas official.
The federal government is directing $20 million toward thinning their ranks. The USDA program involves destroying the wild pig population in two states every few years, starting with the states that have the fewest pigs. Among techniques for doing so are trapping, shooting pigs from helicopters, and sending a radio-collared "Judas pig" to reveal the whereabouts of his group. Meanwhile, some experts are calling for poisoning the animals. In addition to the government program, locals are taking on the task: A church recently sought crossbow hunters to protect pumpkins in Texas, the Houston Chronicle reports, while a hunter in Nebraska recently killed a 400-pound pig; the Omaha World-Herald has a rather alarming picture. (On the bright side, at least the pigs here aren't radioactive.)