Marshy swampy areas inundated with larvae? Sprinkle some Mosquito Bits Quick Kill as a shock. Corn cob granules coated in Bti, the Bits do not last long but provide a punch that will turn water, black with larvae, to a clear pool void of future mosquitoes. Quickly kills mosquito larvae within 24 hours. Environmentally sound biological mosquito control. Sprinkle in any standing water, including gardens. EPA registered in all 50 states. After the initial use as a shock, supplement with Mosquito Dunks for long term control. 30 ounce container with shaker top.