Do Copper Pennies Keep Flies Away?

Specifically, drop four or five copper pennies into a plastic bag half-filled with water, zip it shut, and then place or hang the bag where you want to cut down your fly traffic.

Why do copper pennies keep flies away?

The water and the pennies create a prism that reflects colors, and also projects the image of the water. Flies don't like water, and they don't like the colors given off from the pennies.

Do copper pennies and water keep flies away?

To make your own fly repellent, simply get a gallon-sized zip-loc bag, fill it half to 3/4 with clean water, and drop 3 or 4 pennies in the bottom of the bag. Once the bag is firmly sealed, it can be hung from or nailed to an eave near a doorway to keep the nasty critters from entering your home.