Let’s face you have seen a plastic bag full of water hanged in a doorway or a patio at least once somewhere, and you have probably asked yourself, what is this? And what’s the purpose behind it? Well, some may see it as a weir decor, but it serves a higher purpose than just decoration because it actually helps to deter flies and it helps you keep them away from your household.
Oftenly, people fully fill a gallon size bag with water and put it where they usually put it outside the area where they put food in to keep flies away without using harmful chemicals, others hang multiple bags outside multiple places around the house to keep the flies at bay.
This method works because flies often see the reflection of water moving in the bag and they think that it is a dangerous species that feed on them and they go away fearing death. It is recommended to fill only two-thirds of the bag and give it a gentle and light pound to create the effect, others try to enhance the illusion by placing coins in the water bag.