Mosquito dunks are tablets of naturally occurring bacteria that feed on mosquito larvae. Most mosquitoes — the freshwater species are weak flyers, spawned within a hundred feet of you. That’s in your gutters, where the water gathers. Mosquito Dunks are traps. The mosquitoes are attracted to the standing water, and with that have no offspring. It works. Works even better with the neighbors aboard! Kill Them Humanely!