Posted: Sun Jul 4, 2021 2:03pm
Hello,
This is an old topic but a perennial problem.
My solution to living near a sheep field in England was to stop the flies getting into old wooden window crevices where they like to hide.
One fly attracts others because of the smell of the first and residues left by the first fly, so, cleaning this area - or any place they gain entry to the house is essential. I then used bleach and other cleaning agents to clean or degrade the original traces of flies.
After working in house in France as a house sitter I had exactly the same problem as originally described in this thread. A 7m by 8m room completely covered in a layer of black flies -and I do mean complete, a 2cm layer of dead and dying flies. I used a dustpan, a large bin bag and covered my face with a mask to remove the dead ones.
In trying to fathom out what was happening over the next couple of days of cleaning and removal I noticed the same phenomenon as I had seen in England. The warm wall on one side of the house seemed to be a congregational area. It was also sheltered side from the wind - note the reference to the wind direction previously. In France it was not possible to spray this area but we tried spraying the possible entrance ways into the house from upstairs windows. The lesson for me here was that one building gets picked out as suitable and the rest of the flies join in. Other properties were not affected? I have also noted the same issue with birds in Vera and surrounding areas when looking to buy properties - one property affords sanctuary better than the others and the friends soon follow!
Lastly, perhaps your cooking is better than your neighbours?
Conversely it could be they are using more deterrents in their castles? On the question of bees, the problem is where you spray. The random spraying of crops and fields is dangerous to bees and why the EU have banned certain pesticides but window crevices and walls away from flowers are generally not the environment of bees. For anyone reading this, although I am a bee lover I put human life first and bees second? You can select which insecticide to use too?
Good luck to anyone infected this way.