Kills Mosquitoes before They’re Old Enough to Bite!® The Mosquito Dunks® are America’s best selling home owner mosquito control product. The only product with BTI, a bacteria toxic only to mosquito larvae, that lasts 30 days and treats 100 square feet of surface water.
The active ingredient is (Bacillus Thuringiensis Israelensis) BTI, a naturally occurring bacterium that's deadly to both mosquito larvae and fungus gnat larvae. These dunks can be used in fish habitats, placed in standing water containers such as;flower pots, tree holes, bird baths, rain barrels, roof gutters, old tires, unused swimming pools and even watering troughs. Each dunk kills mosquito larvae for 30 days or more.