They are after grubs, you have to rid your yard of grubs, there is stuff you put on your yard to kill grubs. I have ground squirrels and we bought these spike things at Lowe's that take 3 D size batteries and you insert them into the ground and it make a buzzing noise every 15 seconds, and the batteries are supposed to last for 6-8 months. So far it seems to be working. The little devils have made tunnels all through my flower bed, It is supposed to work on moles also.