Harris Diatomaceous Bed Bug Killer kills bed bug adults, nymphs, and hatchlings. This product is effective and long-lasting when kept dry. Unlike the trigger spray and aerosol egg kill, this powder remains effective as long as it is kept dry, helping to prevent any future infestations. Diatomaceous earth is a naturally occurring powder comprised of crumbled siliceous sedimentary rock that acts like tiny razor blades that cut open the exoskeleton of the bed bug, leading to dehydration. The 8 Oz. comes ready-to-use in a puffer bottle, allowing for quick and efficient application in cracks and crevices. We recommend using this product in combination with the bed bug killer trigger sprays and aerosol egg kill on mattresses and box springs.