@roger,
well, you dont have any crops worth mentioning. Groundhogs eat tender leafed plants and are killers of young soybeans.
I lost several acres of beans last year and I never did whack the several groundhogs that were doing the damage. I blew one of the dens up but , since they have these labyrinths of underground cities (They are a huge prairie dog -like creature), They are not communal but they set up towns of small families that dig their own burrows near each other.
I hd a 10 acre plot pf beans and they nearly stripped it.
Groundhogs ( also known as whistle pigs, woodchucks, and widjiks ) are rel pains in the ass to tractors. They dig these burrows that can catch a tractor wheel and spill the tractor if its only a two wheel drive
22magnums are the correct answer to get em
They dont taste bad either