A small restaurant owner near us has clear baggies
of water, with a penny in each, hanging near all the restaurant doors. We asked
why. He says that the health department fines him for each fly they find at his
buffet. The penny in the bag looks like some kind of fly predator. The flies
stay away from them so they don't come in the doors. I have no idea if
it actually works or he just does it to fun people, but he doesn't have any
flies. I figure it won't cost much to try it around the barn doors. It will
amuse the pony anyway.
