I've tried these but I want to see results and you just never know with the gassers. Once I returned the next day and it was sticking back up through the ground. I've had the best luck with Victor traps. So far on our one acre, I've killed 27 (in 3 months). I've tried black box traps, poison, and "chugging" with no success. I'm still tempted to try attaching a hose to my car exhaust pipe but I've ruled out pouring gas down the tunnel and lighting it . . . might blow up my house.
I agree. This didnt help me much since it seems that the gophers had already build a big network of tunnels. The only way i got results was by using the víctor traps.