 days or longer. Don't worry, mosquito dunks won't harm people, pets, fish, birds, or wildlife. Mosquito dunks are available at garden centers, hardware stores, and online. Visit summitresponsiblesolutions.com. Gary Sullivan here from my friends at Roto-Rooter Plumbing and Water Cleanup. Do you have a few plumbing issues around the house that you've been meaning to fix, like dripping faucets, slow drains, or maybe a garbage disposal that hums more than it works?