My husband and I went and bought DE at Home Depot today to put in our chickens dust bath and sprinkle in the coop as preventative maintenance to avoid mites/lice. From what I understand it's safe but it doesn't say "food grade" on the bag...is this safe for my chickens? I want to be sure before I put it in the coop tomorrow. http://m.homedepot.com/p/Safer-Bran...rth-Ant-and-Crawling-Insect-Killer/202743025/