One day they are in there thick as thieves the next gone for months at a time.
They move around based on the food and water availability.
Ten more years and they will be all over the state.
They're already all over the state. Perhaps not to the point where every time you drive down a road or highway or interstate you see them like blackbirds in a field, but feral hogs have been found or spotted in every county or almost every county.
Turn a domestic hog loose and within a couple of months it will revert to feral status. Same as with a cat or dog. They lose the domestication and it becomes survival of the fittest. Turn loose males and females, or if one or the other hooks up with others, and it's Katy bar the door.