holy hell they are loud nature of the beast ... a lack of nature you mean they fail at their obvious intended purpose in a very humorous manner

As soon the train doors opened I heard the noise. That had to be it. Just as I stepped out of the train it stopped. I wandered around the inside of the station for a few minutes, but it had gone quiet. Then as I went through the turnstiles it sou...

we were unsure of where to look cause we had no idea where it would be. so we just looked around for a little while then went up stairs. Right at the top the noise went. Yep that was definitly it. There was a birds nest right under it with eggs.

Erik the Plaid and I journeyed down the J-Church Muni line to the Balboa Park station. We wandered around the grounds of the station for awhile, looking for signs of the creature. Finding none, we decided to venture inside. (We discovered that by tak...

http://www.bird-x.com/links/ultrasonicbirdrepeller.html