Biological Mosquito Control. Place in standing water wherever it accumulates near the household...Flower Pots, Tree holes, Bird Baths, Rain Barrels, Roof Gutters, Unused Swimming Pools. Each Dunk kills mosquito Larvae for 30 days or more. Use 1 mosquito dunk for up to 100 square feet of water surface. Active Ingredient: Bacillus thuringiensis subspecies israelensis......10% Inert Ingredients..........90%. Rings are 2-1/4 inch in diameter.
