Idaho, Oregon and Washington have launched a “Squeal on Pigs” campaign to raise awareness about feral pigs, stop the pig population from expanding and enlist private landowners in the effort to establish population estimates.

Why? Wild pigs are not native anywhere in the U.S. They spread weeds, disease and cause massive erosion from their rooting and grubbing. The estimate of their damage nationally is $1.4 billion, and that includes depredations on lambs, calves, fawns and birds.

Why are officials worried about a few pigs? Wild pigs start breeding when they are as young as 6 months old and can have four to eight offspring per litter. They can have multiple litters in a year.

How many in Idaho? No one knows. Officials estimated 50 to 100 were living in the Bruneau Valley in 2010 when a multi-agency campaign decimated the known population. But pigs are sneaky and well may have moved downriver into the Snake River corridor. Some were found at the C.J. Strike Wildlife Management Area in 2011.

How did they get here? Some hunters, especially houndsmen, take it upon themselves to bring wild pigs from other states to provide more hunter opportunities. But the pigs — descendants of domestic animals — have been in the Americas at least as long as European explorers.

Report sightings Invasive species councils from the three states are providing a toll-free “swine line” so people to report sightings: 888-268-9219. Sorry, the agencies didn’t provide info on hunting the pigs, but it is legal to shoot them.