I tried out this weird hack to repel house-flies, and it actually kind of works

It's the scourge of every summer: being pestered and eaten alive by bloody flies in your house.

No matter what you do, as soon as you open a door or window, your house gets taken over by the little feckers. The only consolation I can get from the whole nightmarish experience this time of year is that I get to re-use my favourite fake gif of all time - Oprah "unleashing" bees on her audience - as I feel this is the only thing that really sums up the misery that summer house-flies and fruit-flies inflict on us all.     I don't want to tell you how many times I've gotten into actual arguments with flies as I chase the around my bedroom, or try to lure them to the window to trick them into flying back outside. Honestly, that weirdass instalment of Breaking Bad where Walt spends the episode trying to get rid of a fly has nothing on the scenes of me going to war against the buzzing bastards that take over my house.   I clearly let the whole fly situation get to me, so I have spent lots of time researching ways to combat them. Growing up, my dad was a big believer in sticking up fly paper all over our house to catch the little pests.

Via Wikipedia.

But let's be honest, fly paper is absolutely rank, and aside from it being gross to have a fly torture chamber/graveyard hanging in your kitchen, there's the persistent risk of taller people in the house getting their hair stuck to the paper. I've also tried sprays, but they're disgusting to use too. In desperation, I turned to the internet (there's a title for my future autobiography), and that's when I first came across this hack. https://www.youtube.com/watch?v=dLEWz25PvFA   The method involves putting some pennies in water in a clear bag, and hanging it from or near a window. Honestly, that's it. I was sceptical at first, but, in the spirit of 'the simplest solution being the most effective' thinking, I gave it a try. And I have to say, it more or less works. https://twitter.com/Tweet_Dec/status/762213378806939648 It's not 100% effective, but this is the second summer in a row that I've tried this out on my bedroom window, and both times I noticed a massive reduction in the amount of flies coming into my room. You'll still get a few stragglers, but I can almost guarantee you'll see a big fall-off in flying intruders. I don't fully get the science behind it: the explanations online vary, but the best ones I've come across are these:

"...the simple light refraction going through the bag of water that confuses the housefly. I remember learning in my biology days in school that a housefly has large complex eyes made up of thousands of simple eyes that don’t move or focus. The fly bases his movement by light and the refracted light coming through the water in the plastic bag will confuses the fly causing him to move on to a place that is easier to navigate.." And... "Firstly, it is said that it simulates a spider's web, which flies would naturally try to avoid when they can.  Two, the light that reflects off of it is something that the flies do not like.  It causes their many eyes discomfort, or something to that effect, so they stay clear of those areas. It is sort of like how our eyes would experience discomfort from staring at the sun or having a light flashed directly into our eyes. "

In conclusion, I stand by the method. Worth a try, right?