I have a pile out in my side yard of deep litter shavings that I'm trying to compost. I've never done this before. From now on the stuff goes in the birds run, , but I would like to compost the pile already started. So I added some kitchen veggie scraps, newspapers, etc., and then gave it a good water. I never put in meat, meat products, or dairy. Today I noticed that it's nice and hot in the middle which I think is a good thing. But tonight I also noticed that it is covered with flies. I bury any scraps over a foot deep and cover them well so I didn't think flies would be a problem. Am I doing something wrong or are the flies ok?