Thank you! I'm happy to be here.
And thank you for the replies.
There is a place just outside the coop that the flies love, maybe more than they love the run. It's strange because there is no chicken poop there. I do water the tree that occupies the space. I wonder if I may have maggots under the ground too. Maybe that's where all the flies are coming from. I had no idea that was even possible. It sure gives me a place to start though.
I also put up one of those stink fly traps. Oh man they smell, but they work. There were thousands within only a week.