P3 International Sonic Mole Chaser P7900
The P3 International P7900 Sonic Molechaser makes moles scram by  emitting a penetrating sound that sets the rodents' sensitive hearing on edge.  Operating in a circular pattern of 120 feet, the Molechaser also chases off  ground squirrels, shrews, voles, pocket mice, and gophers. It won't harm the  rodents or your earthworms or your pets; it won't even harm your lawnmower,  because you can bury it flush with the ground. At 1-3/4 inches in diameter and  16 inches long, the stout aluminum Sonic Molechaser doesn't require an  excavation of your garden. Plus, you can replace the four D-cell  batteries--approximately once every 4 to 6 months--without digging it up. The  Molechaser gives off 300 Hz of sound at 15-second intervals and works best in  unobstructed, moist clay soil. If soil is dry, sandy, or peat soil, you may need  a couple of Molechasers to get rid of moles for good.--Emily Bedard