I have been noticing a bit of a fly problem, especially around the duck area. They look like the ordinary black flies. They are finding their way inside also. Can I use Seven Dust (5%) to sprinkle around the run area's to help with this problem? I want to use it in the chicken run, duck run, and under the rabbit hutch. My consern is that it will make them sick. Has anyone ever used this and will it harm the flock or the eggs? Can we still eat the eggs if I use the seven dust? Any help would be great.