Feral Pigs Going Hog Wild Across Growing Area of US

Sven Hoppe | AFP | Getty Images

Digging up fields and lawns, killing livestock and spreading disease, wild pigs have gone from a regional nuisance to one rapidly spreading across the nation.

The animals have razor-sharp tusks, a bottomless appetite and no natural predators, and experts say the invasion of the feral pigs has become a major problem that is moving north.

"This truly is becoming a national crisis,'' John Mayer, the manager of environmental science at the Savannah River (S.C.) National Laboratory, told TODAY on Friday.

(Watch the Video: Feral Swine Wreak Havoc in Florida)

The U.S. Department of Agriculture estimates that wild hogs, which can weigh more than 200 pounds, are responsible for more than $1.5 billion in agriculture damage and destruction every year. TODAY's Kerry Sanders took a ride in a helicopter to see them firsthand, watching dozens on the run across the 2,000-acre South Fork Ranch in Okeechobee, Fla.

"It's like having a rat in your house,'' Southfork Land and Cattle Company's Bill Wallace told Sanders. "They're just not a good thing."

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In 1987, there were an estimated two million wild pigs in about 20 states, primarily in the South and concentrated in Texas and Florida. Now there are an estimated six to eight million wild pigs roaming 47 states.

"This increase that we've seen in wild pigs is unquestionably dramatic,'' Mayer said. "We don't have another species here in the U.S. that has increased at this same rate."

Experts say the explosion in the wild pig population is partially due to hunters transporting them across state lines, plus some escaping from hunting preserves. The animals also produce two litters a year, rapidly swelling their numbers.

All of it could add up to a higher grocery bill for Americans. "The reason people should care is because eventually it could result in increased costs at the marketplace,'' Wallace said.