Here is what I do. I use my garden duster. I dust the chicken house and run very good. But mine are free range and I just go around and nail the dust bowls they've made. They are getting plenty enough on them doing that. But I also throw it in the feed container. It helps keep the bugs and moisture out. That way they are getting it internally and externally! I will tell you this about food grade DE. I love it. My dog had mainge last season and it took 250.00 to treat all the animals. This year she came up with it again. So I made sure to dust the heck out of the mainge spot on her and kept a healthy dose in her food daily. That stuff killed the mainge!! It was wonderful! I am a firm believer in DE!! It's great in the garden too!