I live on Guam and was just on a 5 week vacation. My neighbor was taking care of my two hens and one rooster... when I returned the coop and run weren't as clean as I had hoped it would be (but everyone here thinks I'm crazy with the time and energy I spend with on my chickens) with a fair amount of chicken poo everywhere. We also had about 3 tropical storms/almost typhoons which brought TONS of rain. 6-8 inches in one day during the most recent storm. So, my run and coop (but mostly the run) are just laden with flies of all sizes, types, colors, etc... They are all over the run. I do plan to add some compost and maybe pine shavings to their run to dry up the dirt. It isn't muddy but still a bit moist - things don't dry out very fast here. I've also raked everything out of the run and rake it every day now to try and air out the top layer of soil. I washed down their coop with apple cider vinegar and water so everything in their coop is clean again. So I'm mostly wondering - are large amounts of flies bad for chickens? Can it harm them in any way? There were flies before I left but no way was there was many as there are now. I move my hand near the ground and its like the ground is moving when they start flying. I just want to be sure that they won't get sick for any reason ... Advice? Would adding shavings to try and dry things up be enough maybe?