how can I keep the flies down in my chicken run.........

[chickenflicker]

Something you might want to try is taking a gallon size Baggie , fill up half way with water and put one penny in it and hang it in the coop. My neighbor told me about it, she puts one in each of her horse stalls. I was having fly problems in both my chicken and geese pens so put one in each and to my amazement it worked!!! I ended up hanging one on my back porch also. It took a couple of days to work.

 

[Ol Grey Mare]

I assume she's referring to deep pine shavings like most people use in their coops. You would need a covered run for that to keep the bedding dry.

dryness is not necessary. .....think of the forest floor or mulch in a garden....it is exposed to weather but does break down. A good deep layer of organic materiel in the run is great go controlling odor, flies and mud.