If they'd quit putting piles of corn out there would be fewer. We stopped putting corn feeders out for the deer two years ago, haven't seen a hog or even a track since.
I'm not sold on that as being a cause either.
Down here the hogs prefer to stay in the thick creek bottoms where they eat what is there. You don't see them in times of heavy rain and plenty of food. When you do see them again, it's shocking how much they have multiplied.
I do brush control on some ranches where no feeders exist at all. They have hogs too.
The olive farm that I manage has lots of hogs, but no feeders. But it has lots of water...
I'm thinking the water is more critical than the feed. The hogs only seem to spread westward along the waterways.
tain't many in the desert...
