Yes. Mosquito Dunks are described as harmless to fish, birds, frogs, turtles, plants, and beneficial insects, and safe for use around people, pets, and wildlife. Their active ingredient, Bti, a microbial larvicide, targets the larvae of mosquitoes and a few related insects and has negligible direct effects on other organisms.

Why is Bti considered safe for pets and fish?

Because its toxins act on the gut cells of mosquito, fungus gnat, and blackfly larvae, and have negligible effects on other organisms. Bti, short for Bacillus thuringiensis israelensis, is a microbial larvicide, so it works on the larval stage in the water rather than on animals that drink from or live in it.

Where can a dunk be used around animals?

In any standing water animals use, including birdbaths, koi ponds, and animal watering troughs. To keep that water free of larvae without harming the animals that rely on it, one of the Mosquito Dunks is set in the water, treating up to 100 square feet of surface for 30 days or more.

How are dunks used responsibly around wildlife?

By following the label rate and keeping the wider ecosystem in mind. One dunk per 100 square feet of surface water, replaced every 30 days or once it has dissolved, is the documented use, and while Bti is thought to affect few species beyond its targets, removing mosquito larvae may have wider effects on the food web.

Frequently Asked Questions

Can pets drink from water treated with a dunk?

Yes. The dunks are described as safe around pets, and animal watering troughs are among their listed uses.

Are bees and other beneficial insects harmed?

No. The dunks are described as harmless to beneficial insects.

Does Bti affect any insects besides mosquitoes?

A few. It is also lethal to the larvae of fungus gnats and blackflies.

Is the granular form also considered safe?

Yes. Mosquito Bits Biological Mosquito Larvicide, the fast acting granular form of Bti, is described as harmless to beneficial insects, pets, birds, fish, horses, and livestock.