Why are people hanging bags of water above their doors?

As the summer months roll around, many of us find ourselves battling an age-old annoyance: flies and other pesky insects. These uninvited guests can make outdoor gatherings and indoor spaces uncomfortable and unsanitary.
In response to this perennial problem, a peculiar yet widely adopted hack has emerged: hanging bags of water above doors and in other strategic locations. But why are people resorting to this seemingly odd solution, and does it really work?
The Water Bag Hack: How It Works
The basic premise of the water bag hack is quite simple. You’ll need a few common household items:
A heavy-duty freezer bag
A sprinkle of table salt
A splash of lime juice
A few coins
Water
Here’s how you put it all together:
Fill the Bag: Start by filling the heavy-duty freezer bag with water, leaving a small amount of air inside to prevent it from bursting.
Add the Ingredients: Sprinkle in a small amount of table salt and add a splash of lime juice. Drop a few coins into the bag as well.
Seal and Hang: Seal the bag securely, ensuring it’s airtight. Hang the bag above your door or any area prone to insects, making sure it’s in a location that reflects sunlight or indoor lighting.
But how does this seemingly strange concoction deter flies and other bugs? The answer lies in the way these elements interact with light and affect the insects’ behavior.
The Optical Illusion
When sunlight or indoor lights hit the bag filled with water, coins, salt, and lime juice, something fascinating happens. Flies and other insects are sensitive to light and perceive it differently from humans. The bag of water creates an optical illusion that can disorient these insects. Here’s how it works:
Reflection: The water-filled bag acts as a reflective surface, causing the light to bounce off it in various directions.
Movement: The coins and the water inside the bag move due to air currents and the bag’s own weight, creating a dynamic and ever-changing play of light and shadows.
Disorientation: When flies encounter this constantly shifting, reflective environment, their visual perception is disrupted. They have difficulty focusing and navigating effectively.
Deterrence: Over time, flies may become frustrated or disoriented by the distorted visual cues, making them less likely to linger around the area with the hanging bag.
A Humane and Chemical-Free Solution