Here is an interesting product I ran up on that keeps birds from running into large glass doors or windows. My folks have a place in the mountains with lots of glass that birds run into very often. They have tried placing decals on the glass with mixed results. I sent them info on this product and they are going to try it out. Birds see UV light that we do not see. The decals reflect the sun's UV light so that the birds see the glass and avoid it.