Keep flies away with a clear plastic bag filled with water with penny at bottom! It's completely non-toxic, and you can picnic fly-free! Fly repellent - pinner said "I had to repin this again for you to see. YES IT WORKS! Oh my, it looks hokie but our temps have been upper 90's and no flies in my back yard have been spotted. I spoke with a women who grew up on a dairy farm and she swears by it. She said they used 5 pennies. Go figure."