The interesting thing that this video does not show you, is that they are likely killing some of the animals on purpose. A USDA Wildlife Management employee on

The interesting thing that this video does not show you, is that they are likely killing some of the animals on purpose. A USDA Wildlife Management employee once gave a presentation on various pest animal control techniques to my class of wildlife science students. He spent some time controlling birds at airports. Birds learn that noises do not kill them. Eventually they ignore the noises. To fix this, every once and a while he had to make a kill with the stimulus. Some of the techniques in the video may not require occasional kills. I would love access to their logs. It would be interesting to see if indeed they are making occasional kills and how long it took to find the optimal interval.