As you are so close to your neighbours, could it be something in their gardens?
I lived in a flat once where I was above the room with the communal bins. One summer someone must have put something in that was a feast for maggots because that whole side of the building was infested with bluebottles for weeks coming in every time a window was opened.
In the meantime, as you hunt down the source, put up some fly sticky paper traps around inside your house. They are cheap and have some sort of scent that attracts flies. I've used them on the summers that we get tons of hatchlings of houseflies in our area.. and I expect they work for Bottle flies too. Unsightly, but effective.
As you are so close to your neighbours, could it be something in their gardens?
I lived in a flat once where I was above the room with the communal bins. One summer someone must have put something in that was a feast for maggots because that whole side of the building was infested with bluebottles for weeks coming in every time a window was opened.
I think Bob's slug pellets suggestion is the cause. My neighbours' yards are barren with closed and tidy wheelie bins. I can live with them. They sleep on a night. Quite creepy but better than flying around my head. Lol.
In the meantime, as you hunt down the source, put up some fly sticky paper traps around inside your house. They are cheap and have some sort of scent that attracts flies. I've used them on the summers that we get tons of hatchlings of houseflies in our area.. and I expect they work for Bottle flies too. Unsightly, but effective.
I would try that but we have a cat who would go crazy hunting them down. I'd end up constantly claiming on my home insurance! Lol. We have "flat cats" up at all of the windows so at least they can't get in.
Posts
I lived in a flat once where I was above the room with the communal bins. One summer someone must have put something in that was a feast for maggots because that whole side of the building was infested with bluebottles for weeks coming in every time a window was opened.