Have you ever noticed a small coin taped to a kitchen window? You might see this unusual trick used by people who value tidiness, want to save money on cleaning products, or travel frequently. At first glance, it looks like a superstition meant to attract wealth. However, the reason behind it may be far more practical—which is why some people are willing to try it at home.

An unusual way to combat grime

Kitchen windows are constantly exposed to grease, steam, and tiny droplets generated during cooking. Over time, an invisible film forms on the glass, easily attracting dust and dirt.

Proponents of this hack suggest taping a small coin to the bottom of the window frame. The theory is that metal and glass heat up at different rates in the sunlight, creating slight variations in temperature and humidity around the coin.

This is how some explain the potential reduction in grime buildup on the glass. However, there is no conclusive scientific evidence that a coin actually prevents the accumulation of kitchen grease.

What about flies and wasps?

There is another popular explanation for this method. The shiny metal surface reflects sunlight, creating small glints or flashes. It is believed that these reflections can disorient certain insects, causing them to change their flight path.

For this reason, the coin trick is sometimes used as a simple home experiment during the warmer months, when windows need protection from flies, wasps, and other flying insects.

The secret might also lie in psychology.

There’s another, completely different explanation. Any noticeable detail in the kitchen can remind you to keep things clean.

Seeing the taped coin might prompt a person to pay closer attention to the condition of the window, the frame, and the kitchen as a whole. As a result, cleaning might actually happen more frequently—not because of the coin itself, but thanks to the habit you’ve formed.

How to try this life hack

If you want to test the method yourself, take a clean coin, wipe it with alcohol, and attach it to the bottom corner of the window frame with a small piece of clear tape.

Observe the results for a few days. Just don’t expect a miracle: the coin won’t replace regular cleaning, and no scientific evidence shows it repels insects or prevents grease buildup on the glass.

On the plus side, the experiment costs practically nothing—which is why this unusual kitchen hack keeps sparking interest.