Dogtek's Sonic BirdHouse has the appearance of an ordinary birdhouse but in fact, it's a state of the art bark control device the uses high-pitched ultrasonic sound technology to deter unwanted barking from either your or your neighbour's dogs! When the Dogtek Sonic BirdHouse is installed within the range of a barking dog, the internal microphones sense the barking and the unit is triggered automatically. The Dogtek Sonic BirdHouse emits an ultrasonic sound which is heard by dogs but is not detected by humans. The dog will stop barking when The Dogtek BirdHouse emits it's high-pitched, safe and effective tone. The dog will begin to associate their bark with this unpleasant noise. When the dog stops barking the ultrasonic tone will also stop.