A natural, nontoxic way to control mosquitoes before they become flying, biting, disease-carrying adults. Each Mosquito Dunk kills mosquito larvae for 30 days or longer Each Dunk covers up to 100 square feet of water, regardless of depth For Outdoor Use Easy to use, simply place a dunk in any standing water once a month or as needed Approved for use around fish, birds, wildlife, people, pets and plants Approved for Organic Production and Gardening For smaller areas of standing water, such as bird baths, rain barrels, small ponds, etc. Dunks can be broken into pieces 6 Dunks per package Unused and dry dunks retain potency indefinitely