M-7 for fleas comes in a powder form. It mixes with water and can be applied through your steam machine or a pump sprayer after cleaning. When the carpet dries, M-7 crystallizes and creates a dry environment that hardens soft flea eggs. If a flea hatches, sharp crystals cut up the newborn flea. The flea cycle lasts about two weeks, and M-7 will last about one year or until the carpet is re-cleaned. This product really works! Safe for pets and rug crawling infants. Harmful only to fleas.