Out of no where we have gotten a huge amount of house flies in our garage (attached but no entry to the house) and in our front windows (inside our house). This was about 3 days ago. They all congregate on the inside of our garage door (I’m taking 40+ flies). We’ve bought zappers and tape, etc. but they keep coming back. We’ve removed the trash and checked to make sure there was nothing in the garage they may be attracted to. We cleaned out our garage and sprayed it down with a bleach-type cleaner. Any ideas as to what might be attracting them, or how to get rid of them? We live in southeastern PA, for reference.