For several years I've been plagued by gophers. I have dogs that would like to help me root them out and so they've had to be confined to a pen that has chicken wire to prevent the digging (the only time they dig is to go after the gophers). My yard looked like it had the measles from all the gopher mounds and mowing was a real drag. I did get smelly things, tried all the organic methods I could find from garlic to peppers to castor oil sprayed on the runs (apparently they don't like that). There was no change. I just hate to kill them! This little thing did the trick. I live in clay soil so I guess it's helpful but the mole holes have completely stopped. There is no evidence left that they like my yard. I bought two and put them one in the front and one in the back but the gophers in the side yard seem to be gone too. I'm on just under 3/4 acre. I think the change is these devices as the timing was right but as soon as it warms a little more here, I will know for sure. I'm pretty sure already as I was getting new mounds of activity and they have completely stopped, so I'm thinking these babies did the job. Yippee, no gophers! Maybe I can let the dogs back into the big yard!