Make friends with ‘em. Train ‘em to do tricks. Pet ‘hogs...quite a novelty.
Ah, they already do tricks. They have these wonderful parasitic flies trained and every time they go into their hole, the little flies jump off, sit on the porch and wait for their hosts to come back out. Unfortunately, the flies like people, too. You can spray and spray, and more flies find the groundhogs. Great trick!!
Seriously, lots of good advise here. I’ll check the rock tomorrow and see if Phil has come back and started digging again.