Diatomaceous Earth is created by grinding up the fossilized shells of tiny water-dwelling organisms called diatoms. The ground-up diatoms have microscopically fine, sharp edges that cut the exoskeletons of insects. Diatomaceous Earth is used as a barrier to crawling pests such as slugs, snails, and earwigs. DE loses its effectiveness when wet but regains it when it dries out again. Apply in the early morning or evening to minimize disruption to beneficial insects. Our food-grade DE available in a 50 lb. bag can be added to animal feed as an anti-caking agent. Use a mask to avoid breathing the dust.