They won’t spread far here. We have over 300 million privately held guns.
Folks might shoot them, but prosecutions would follow. One of my friends killed a bunch of squirrels that were invading his attic and ruining his yard. He hung them on the fence as a deterrent. He got a ticket from the LEOs.
It wouldn't do any good unless we could display the bodies surrounded by rooting sows and boars and peeing dogs, send videos all over tarnation, and let them stay laid out in public until the buzzards eat them, and then cover them with bacon and let the wolves out. Even then, it won't stop until Christ returns in glory and every knee shall bow. But it might slow them down.