The active ingredients in products used by the District include Bacillus thuringiensis subspecies israelensis (BTi), Bacillus sphaericus (Bsph), Spinosad, Methoprene, mineral oil, and garlic. BTi, Bsph, and Spinosad are all biologically derived from naturally occurring soil bacterium that causes mortality to mosquito larva after ingestion. BTi is used specifically for black fly control, causing larval mortality after ingestion.

Methoprene is an insect growth hormone regulator that mimics the juvenile growth hormone of mosquitoes, not allowing them to fully develop into adults. Mineral oils cause suffocation of mosquito larva and pupa and is selected because it breaks down quickly in the environment. Garlic is microencapsulated in a sugar bait. When ingested by mosquitoes, the garlic acts as gut toxin.