Here are a couple of prior responses on that issue that might be of help -
https://answers.angieslist.com/best-r...
Of course, strychnine laced bait works best, but illegal in most areas and has to be hidden down in the tunnels so pets can't get at it - works for gophers, of course basically no bait works for moles because they don't revisit old tunnels much - always moving ahead in the world, so to speak.