Gophers, prairie dogs. groundhogs, moles, holes. All the same techniques.
When I had my farm, I tried setting up a rich mixture on my VW, plugging up one of the exhaust pipes, adapting a hose to the other, shoving it into the prairie dog holes as far as I could, and running the engine for a while. Then I pulled the hose and covered the hole. Although no evidence of dead ones appeared, no more holes showed up for quite a while, This actually seemed to work in that respect. They were sneaking in from the neighbor's property and rhe holes endangered the horses.
I used to do a lot of prairie dog "thinning" for the farmers hereabouts with a .223 Remington out of my beloved ancient antique Savage ( 1-14 twist, 53 grain bullets, 3031 for about 3k f/s), but that's all you can do with a rifle -you can't actually eradicate them that way unless you do it every day and have unlimited handloads.
I used to call this operation "Feeding the raptors."
Trouble is, with modern cars, you can't diddle with the fuel mixture unless you hack the computer, I guess. And you can't hardly find a .223 rifle with a 14inch twist any more, either.
Terry, 230RN