Flies are those tiny uninvited guests that can turn a peaceful afternoon into pure frustration. Whether you’re trying to enjoy a meal outside or simply keep your kitchen clean, they always seem to show up at the worst possible time.
Over the years, I have tried sprays, traps, and gadgets—most of which were expensive, messy, or only temporarily helpful. Then my mom shared her old-fashioned trick. It takes just five minutes to set up, costs almost nothing, and keeps flies away naturally. Here’s how it works.
Why Flies Are Such a Problem
Flies aren’t just annoying—they can carry harmful germs. The World Health Organization warns that they spread bacteria that cause diarrhea, cholera, and typhoid fever. With their strong sense of smell, flies can detect food from up to four miles away. Combine that with their fast breeding cycle (one female can lay 500 eggs in her lifetime), and it’s no wonder they’re hard to control.
Why Sprays and Traps Fall Short
Most people turn to chemical sprays or sticky traps. While they may work for a little while, they come with downsides:
- Sprays can be harmful to kids and pets.
- Traps are unsightly and need constant replacement.
- Neither actually prevents new flies from coming in.
That’s why my mom’s method feels like a breath of fresh air—it solves the problem without the chemicals or clutter.
Mom’s Surprising Trick
Her secret? A simple plastic bag filled with water and a few shiny coins.
It sounds odd, but people have used this trick for generations. The hanging bag works like a prism: the light bouncing off the water and coins confuses a fly’s compound eyes, making the area seem unsafe. Instead of coming closer, flies steer clear.
How to Set It Up (Takes 5 Minutes)
You only need:
- A clear plastic bag
- Water (fill halfway)
- 3–5 shiny coins (pennies or nickels)
- String or twist ties
Steps:
- Fill the bag halfway with water.
- Drop in the coins.
- Seal it tightly to avoid leaks.
- Hang the bag near doors, windows, or outdoor eating areas.
That’s it! Within minutes, you’ll notice fewer flies buzzing around.
Why It Works
Flies have compound eyes made up of thousands of tiny lenses. They’re excellent at detecting movement and light changes—but that’s also their weakness. The bag of water with coins bends and reflects light, creating a kaleidoscope effect that disorients them.
The result? They avoid the area altogether. No chemicals, no zapping, no hassle.
Real-Life Success Stories
Plenty of people swear by this hack. Sarah from Texas said her family barbecue was the first one without flies buzzing over the food. Tom from Florida hangs the bags in his garage and hasn’t had an issue since.
How It Compares to Other Methods
- Cheaper than sprays or electric zappers
- Cleaner than sticky traps
- Eco-friendly and safe around kids and pets
Once you set it up, you don’t have to touch it again for weeks. Just replace the water and coins if they get dirty.
Quick FAQs
Does the type of coin matter?
No. Any shiny coin works.
How long will the bag last?
Several weeks—refresh it if the water clouds or coins dull.
Can I use it indoors?
Yes, but it works best with natural light.
Final Thoughts
Flies may be persistent, but keeping them away doesn’t need to be complicated. My mom’s water-and-coin trick proves that sometimes the simplest solutions are the most effective.
It’s quick, safe, and budget-friendly—and once you try it, you’ll wonder why you ever bothered with sprays or gadgets. Hang a bag today, and enjoy a fly-free space tomorrow.
