The pigs, which are thought to have escaped from private shooting preserves or from illegal transport by hunters across state lines, are causing serious problems, especially to farmers and ranchers, because they "rototill fields, dig up lawns, decimate wetlands, kill livestock, spread diseases like pseudo-rabies and, occasionally, attack humans," Goode reports. “The conundrum is that you’ve got one of the world’s hundred worst invasive animals, and at the same time you’ve got a highly desirable game species,” said Dr. John Mayer, the national lab's environmental science director. “It’s a real Jekyll and Hyde type situation with wild pigs.”
Many other countries have similar problems, Jesse Hirsch writes for Modern Farmer: "The fact is, wild pigs have overrun the planet." Nearly half the wild pigs in the U.S. are in Texas, which reports having 2.5 million, Mike Tontimonia reports for Farm and Dairy. This map shows where wild pigs were reported as of November 2011. For a larger version, click on the image; for an interactive version, click here.