On our lease they're mostly nocturnal. We occasionally kill one when hunting, but not often.

We use two large traps (10' long, 6' wide, 4' high) to keep the population in check. They are made with heavy highway mesh, have guillotine type doors and a trigger system something like box traps for rabbits. We block the door open and bait with a big pan of soured corn. After they've emptied the pan a few times we set the trigger for a catch. The thing is, once a group of pigs are used to going to the bait they will all rush in together trying to beat each other to the fresh pan of bait, and we catch a whole group at a time.