After hiking Old Rag Mountain last Friday with my wife, we stopped in Sperryville for a late lunch at Burgers and Things. I noticed that some zip-lock plastic bags full of water were attached high on the walls of the cafe. When I inquired about the water bags, an employee said that they keep the flies out. She continued to explain that flies have compound eyes and that when they see the bags full of water, they think it’s raining and therefore keep clear of the area. The idea sounded a bit far-fetched to me; however, not a single fly could be found in the cafe.
What do you think of the science behind this theory? Feel free to post your opinions and/or results of any experiments.