I saw bags of D E on the shelf. I read the lable . It says that it will kill most crawling insects .But I see no food grade on it any where looks like they are selling it just as an insectacide.. It says it can be used in pet quarters but don't breath the dust. What is the differance between food grade?might just be the labeling?The product name is Safer. This has been on the shelf quite a while... I think I can pick these bags up cheap . because it is dead shelf space . what about it can I use it in the chicken yard ? Maybe & not get in the feed?--- hard to pass up a deal these days---- but don't want to kill the hens.