I have two pieces of it used against my voles in the garden. These beasts bestowed me around 15 holes on a slope and on the lawn, despite that I already use an ultrasonic transmitter. This is very weak to fortuitous only in winter, because the batteries are only slightly charged via the solar cell. Anyway, I have set on 350 m² two pieces of vibration motors in the earth, because I have quite a height difference in the meadow and the hillside. (3m) After a week of no new hole was visible. And after I have now closed the old holes, you can clearly see that no new hole is more signed agreements. Absolutely Top! All rodents away. Tip without poison !!!!!!