What is with the flies?

[Mama Runner]

I have not had a problem with flies in the coop all year. It finally got cool last week. Before hopping on the plane I cleaned my coop really well and the flies were horrible. Is this just the time of year?
I did put some DE in before putting in fresh bedding. Any ideas? Anyone else having issues?

 

[sourland]

In the colder weather they are seeking warmer spots to over winter.

 

[ChickensinAfrica]

If you can't get rid of the flies why not stop them from breeding and turn them into chicken food...

 

[FlyingNunFarm]

I'm having a horrible fly problem! I liken it to a horror film. Not only are they in the coop they are in my house! It's disgusting. I've tried everything. Over the summer I put out those smelly bag type traps. The flys loved them. I had to put new ones out once a week! Now they won't go in them. Put sticky traps in the windows in the house. I've caught one fly. ONE! I'm at my wits end here. If you find something to get rid of them let me know!