Mosquito dunks: safe for pets, deadly for mosquitoes

Bacillus thuringiensis israelensis (Bti) is completely safe for pets, fish, frogs, birds, and basically everything else that isn’t a mosquito or black fly larva.

The way Bti works is incredibly specific. It produces a protein that only becomes toxic inside the alkaline gut of certain insect larvae. Mammals, birds, amphibians, and even most other insects have acidic stomachs—so the toxin never activates. It’s like a key that only fits one lock.

Plenty of studies back this up. The EPA, the WHO, and every major environmental agency have reviewed it. You can drop a dunk in your pond and let your dog swim in it the same day. The bacteria degrades within days in water and doesn’t bioaccumulate.

The only real risk is to the mosquito population. Which is the entire point.

Future generations of mosquitoes will not thank you, but your fish will.