How do pennies keep flies away?

Answered by James Kissner

Pennies, believe it or not, can actually be quite effective at keeping flies away. The concept behind this method is based on the theory that the reflection and refraction of light off the shiny surface of the pennies can confuse and disorient flies, ultimately deterring them from sticking around.

When light hits the bag of water filled with shiny pennies, it causes the light to refract and scatter in multiple directions. This scattering of light can create a visual disturbance for flies, making it difficult for them to navigate and find their way. It’s like shining a bright light directly into someone’s eyes – it can be disorienting and cause them to look away or move elsewhere.

The reflective properties of the pennies, along with the movement of the water inside the bag, further adds to the confusion for the flies. The combination of light reflection, refraction, and movement can create a dynamic visual stimulus that overwhelms the insects and makes them feel uncomfortable or threatened. As a result, they are more likely to fly away and seek a calmer environment.

It’s worth noting that the effectiveness of this method may vary depending on the specific circumstances and the type of flies you are dealing with. Some insects may be more sensitive to light disturbances than others, and the success of this technique can also depend on factors such as the size and positioning of the bag, the amount of light hitting the pennies, and the presence of other attractive stimuli for the flies.

In some cases, people have also used pieces of aluminum foil instead of pennies to achieve similar results. The reflective surface of the foil can create a similar visual disturbance for flies, potentially deterring them from staying in the area.

While there is some anecdotal evidence supporting the efficacy of using pennies or aluminum foil to repel flies, it’s important to remember that this method may not be foolproof. Flies have complex sensory systems, and they are attracted to various factors such as food, odors, and warmth. Therefore, it’s always a good idea to combine this technique with other fly deterrents, such as keeping your environment clean, using fly screens on windows and doors, and disposing of garbage properly.

The use of shiny pennies or aluminum foil to keep flies away is based on the idea that the reflection and refraction of light off these surfaces can confuse and disorient the insects. While it may not work in all situations or for all types of flies, it can be a simple and inexpensive method to add to your arsenal of fly control techniques.