Whenever your dog – or your neighbor’s dog – barks, he will hear a safe, high-pitched sound (inaudible to most humans) that will cue him to stop his annoying habit. Modeled to look like a birdhouse, the bark controller is battery-operated and has three settings plus a test option. Our ultrasonic outdoor bark control unit looks like any ordinary birdhouse that can hang in a tree, on a fence post or anywhere outside.