I know there have been other threads on fly control but I can't seem to find the one I read the other day. I'm not sure why but thought I'd share that we were told to put vanilla in our rabbits water because it would be in their pee and repel flies. We tried it and it made a little difference but not too much so we started thinking that if it is the smell that the flies don't like, we would just sprinkle vanilla in the coop and see if that helped. I used about two tablespoons of pure vanilla extract and sprinkled it around the bedding in the coop and along the window sills. I also put some on my hands and rubbed it all over the cages of the rabbits. When we came out to check a couple of hours later there were only four flies in there. So it didn't totally eradicate them, but it really helped A LOT. We then went out and bought some of those car air fresheners scented with vanilla and hung three of them (our coop is 9 by 14). There's a few flies today but nothing like they are outside. I'm so happy to get them under some kind of control. Plus our coop no longer smells like a barn ... it smells like car air freshener. Ha.