I'm having problems with groundhogs right now under an old milk barn.They've dug under the concrete apron and I'm concerned it's going to come apart. I've already taken 6 groundhogs from that area this Spring. Last year, I took 5. I need to find a better way to get them to move on.
Start covering the holes with 220's.
Might be good for a couple more.
Be sure your dogs don't poke their heads in there though. LOL