House flies are unwanted not only because they are a nuisance but also because they are thought to have the ability to spread organisms that carry diseases—bacteria, for example. House flies can breed in garbage, thus multiplying within the home.
To control flies in the house, it’s important to control their feeding and breeding opportunities. Because flies consume rotting organic matter, it’s important not to leave any out. Garbage should be kept in sealed bags inside trash cans with covers on them. Outdoor garbage containers should be keep far away from the home. Organic materials—animal manure, for example—should not pile up outside; it should be cleaned up right away. And should trash become infected with maggots, you should get rid of it immediately. If food has spoiled, it should be trashed right away. If it has spoiled, flied may have already laid eggs within it, which brings maggots. To keep flies from coming in your house, it’s important to seal places of entry—windows, doors, etc. Caulking may be used to seal up holes. Screens should be checked for holes, and any holes should be patched—or screens should be replaced.
To destroy the flies, fly paper can be effective in a small area. Ultraviolet traps may also be used as flies are drawn to the rays and get trapped once inside. Synergized pyrethrins or synthetic pryrethroids in spray form or aerosol can kill flies. This method is most effective when used in closed rooms. There is also, of course, the good old flyswatter. It may be most effective to use two flyswatters and to come at the fly from different directions. After all, they are quick to respond when being swatting at. If your home is severely infested with flies, residual insecticide may be used by a professional exterminator. However, be aware of possible side effects of using toxic chemicals around your home.