This natural white powder, made from fossilized diatoms, acts as a dry pesticide for crawling insects. It works well for fungus gnats in house plants, just sprinkle a thin layer across the surface of potting soil. Note- for it to be most effective, use halfway between waterings when the soil is as dry as possible, as it becomes ineffective once damp. Safe to use around both humans and pets, though prolonged exposure to airborne particles is not recommended.Refillable in the shop!