Main Page | See live article | Alphabetical index Fly spray is a chemical insecticide that comes in an aerosol can that is sprayed into the air to kill flies. Fly sprays will kill house flies, blowflies, spiders, ants, cockroaches and other insects. Cool Stuff kills bugs and junk, also good for throwin your bed around... Active ingredients of most fly sprays are permethrin and tetramethrin. Which act on the nervous system of flies. Fly spray should be used indoors, and each room of the house sprayed should have its windows and doors shut. This article is a stub. You can help Wikipedia by fixing it. This article is from Wikipedia. All text is available under the terms of the GNU Free Documentation License.