Fly infestation!

>>18545006
They are dying
Clean your fucking appartment and actually take out the rotting food

Your neighbor had/has an infestation and sprayed his place. The poisoned pests came to your place to escape the torture, but had received a lethal dose already.
There is a hoarder slob living near you.

In the US, we have foggers available at the grocery store for a few bucks. I came home from vacation once and there were flies everywhere. I used a fogger and never saw them again.

remove food
vacuum the eggs on the floor
have an open window

they'll be gone in less than 2 days

>>18545557
leave the window open=less flies