Apparently it's some sort of fly repellent. One theory is flies don't like to fly under water, so you are supposed to hang it over the doorway. That's not where the neighbors' have it.
Another theory is the water in the bag magnifies the flies as they approach it and it freaks them out. Again, it's not really in a place a lot of flies would pass. So I have no clue.
The general consensus, though, is it doesn't work.

---Posting from my iPhone every day in 2010













