Diatemation Earth ( not spelled right) It is also know as FOOD GRADE Fossil shell flour. It is a perhistorical fossil shell ( hence the name) that is 100% natrual for pest control. It kills worms internally, can be used as a dust for lice, mites, flea, ticks. It is safe for humans , horses, cattle, chickens, dogs, cats to take internally. I mix some in with my lay crumbles so the ingest it on a daily bases and have never had a problem with parisites.