Great idea, I remember, now, hearing about this before. The story I read was from a RV'r (camping). I believe what he suggested was to hang a 'clear bottle' of water next to where you want them repelled. Again if I remember right the bottle\ziplock bag of water would confuse the vision of the flies by the reflections.The Helpful Gardener wrote:Just learned a trick from a Filipino friends mom; we were eating and the flies swarmed the table. She came out with two ziploc bags filled with water, plopped them on the table, and voila! the flies vanished. Mom says it's feng shui; I don't care if it's The Force, I have seen it work and how! I am assured this works every time...
My suspicion is that water draws dragonflies, so once flies see water they scoot before the dragonflies show, but I am just guessing. Try this, you will be amazed...
I'll see if I can find something about this, it was a several years ago.
And we have tons of dragonflies around here, the size of jumbo jets.
Did a quick search and came up with this, thanks for reminding me HG
(Quote) "Okay guys, I have the low down on this....I have family all over Mexico and travel down there quite a bit. This myth is REAL!! Lots of people in Mexico and elsewhere in Latin America hang small plastic bags from doorways to repel flies. The myth says that as flies approach the entrance and they look at the bag of water their vision becomes incredibly scrambled and drives them crazy! Remember that according to science flies have several eyes or some sort of kaleidoscope like vision. Apparently the water in the bag mirrors their image many times over and drives them insane."
here is another slightly different explanation but still confirms that this works. https://www.lifehacker.com.au/2009/07/repel-flies-with-a-bag-of-water/