Cat chaser for yard use 1,New patent product 2.long-range passive infrared (PIR) sensor 3.110 degrees Cat chaser for yard use(AN-B010) The frequency emitted by ultrasonic animal repelling devices is carefully calibrated to be uncomfortable for the dog,bird,cat,mouse etc, making them run away from you. However, it is not harmful, and will not damage their hearing or produce any other consequences. ...