Ground hogs can be very destructive with their digging. There is no season on them in Illlinois, you can shoot them any time. We have old dog kennel where we live. A very fancy dog kennel that is made out of concrete, maybe a total of 800 sq ft. They have just about destroyed it by tunneling under it. I don't use the kennel so no big deal, but I don't want them under my shop. I've shot about 15 of them, either with a shotgun with 00 buck or my mini 14. They have great eye sight, so I've shot most of them with the mini 14 hiding in the back shadows of my garage. I would recomend at least a 223. I don't think a regular 22 long rifle would anchor one with one shot on a regular basis.