Quote Originally Posted by Al G View Post
Really? How does it work?
As I was told and how I understand it is with the flies multitude of eyes the feedback to their eyes from looking in to a bag of water scares them away. At the place I retired from you could only smoke in one designated area and we built an 4'x8' smoke shack for inclement weather. Some people would eat their lunch there and in the summer the flies would get pretty thick. Hanging a clear water filled bag from the ceiling pretty much solved the problem.