Mosquito Dunks are effective against mosquito larvae in standing water, with each dunk controlling them for 30 days or more across up to 100 square feet of surface. They work only on the larval stage, so they stop new mosquitoes from developing in the water rather than killing adults that are already flying.

How do mosquito dunks work?

By releasing Bti, short for Bacillus thuringiensis israelensis, into the water. Bti is a microbial larvicide, a biological treatment that targets only the larval stage of the mosquito, so treating standing water stops the larvae before they become biting adults.

Where should a mosquito dunk be placed?

In any water that stands long enough for mosquitoes to breed. Placing one of the Mosquito Dunks in a rain barrel, bird bath, koi pond, gutter, animal trough, or a water filled hole in a tree treats up to 100 square feet of surface water, regardless of depth.

How often are mosquito dunks replaced?

Every 30 days, or sooner once the dunk has fully dissolved. Each dunk controls larvae for 30 days or more, so a monthly replacement keeps the water covered without a gap.

Frequently Asked Questions

Are mosquito dunks safe around pets, birds, and fish?

Yes. Mosquito Dunks are described as harmless to fish, birds, frogs, turtles, plants, and beneficial insects, and safe around people, pets, and wildlife.

Can water from a treated rain barrel go on plants?

Yes. The dunks are listed as harmless to plants.

Can mosquito dunks be used in an organic garden?

Yes. The product is approved for organic use.

Is there a faster acting option than a dunk?

Yes. Where larvae are already hatching, Mosquito Bits Biological Mosquito Larvicide sprinkled over the water releases all of its Bti at once for a quick kill within 24 hours, and is reapplied every 7 to 14 days.