Fungus gnats will commonly breed in the soil of house plants that may have too much moisture. Bac-A-Zap is labled for drain flys, phorid flys and fruit flys but it does not actually kill them, instead it has an enzyme that helps break down the organic matter that these flys breed in. This type of treatment will not work on fungus gnats. You should read our "Getting Rid of Gnats" article that explains how to treat fungus gnats. We recommend using Talstar P which can be sprayed directly on the soil to help control fungus gnats and we also recommend letting the soil dry out completely between waterings.
Answer last updated on: 10/09/2009