We've never bought these devices to test them, but we have encountered them. Simply, they do not work. In fact, a wildlife biologist taught us recently that birds hear less of the auditory spectrum than humans do, and that their range of hearing is within the human auditory spectrum. Therefore, if we don't hear the "ultrasonic" noise, NEITHER DO THE BIRDS!!!

We have never bought one to field test it, however we have encountered these systems quite often. Frequently, we get called in to do jobs at sites where facility managers have already installed squawk box systems. If the systems actually worked, we would never have been there to know about it. Our technicians wind up throwing those types of systems out on a regular basis.

The facts:
Most urban pest birds only have a 2 to 3 year lifespan, therefore many have never been exposed to the predatory birds whose calls are projected from the speaker systems. They don't know to be afraid of the noises. Besides, in urban environments, birds hear constant sirens, horns honking, construction related noise, and even the occasional gunshot. Birds are not going to be scared off by a little screeching. In fact, it will be more annoying to you and me than to the birds.

There are an extensive number of variables which make pricing for jobs a real challenge without a site inspection. Environmental factors come into play which may mean that differently designed systems are needed for two identical buildings.