I found Gopher Gasser cartridges at a local store, and picked some up.
You get ready to plug the hole, light the thing and toss it in and then quickly plug the hole with dirt.
It also reveals where the other openings are so you can get them.
I have not seen one woodchuck around our place as of yet. But mr. mm thinks we have a stray cat living under our garden shed so that may be the help.
We also have owls around. I don’t know if that helps or not.
Course, I’m looking forward to taking care of any with 9 mm. I’m a pretty good shot with targets, but have not yet tried on moving ones.
We tried those gas cartridges last year. She just moved her den from under the barn to the side of the hill nearer to the garden .