This is interesting. I've been researching. The northern states take pig invasions seriously. They'll hunt them down with airplanes if they have to. There are report-a-pig programs. Maybe we're too slack and that's why we have problems
$1:
The states of Washington, Idaho and Oregon have banded together with a “Squeal on Pigs!” program, urging people to report sightings of feral swine — although, in Oregon at least, they mostly come from California and not from Canada. Bush estimates they get a couple calls per month about pigs on the loose, so that there can be a co-ordinated government response.
“You can’t shoot your way out of it, recreational tools and techniques just aren’t effective eradication techniques,” Bush said. “It doesn’t matter if it has tusks, or it looks like Wilbur the friendly pig, if it’s out of captivity, call this number immediately.”
https://nationalpost.com/news/canada/in ... eral-swine