To eliminate attic flies, also known as cluster flies, swat dormant flies with a fly swatter, then spray remaining active ones with insecticide and vacuum/sweep up the dead ones for disposal. This process may require checking the attic over several days or weeks to make sure the problem has been solved. For severe infestations, it may be necessary to call an exterminator.
- Use a vacuum or fly swatter
Because cluster flies are half dormant when indoors, it is easy to get rid of them en masse using a fly swatter or a vacuum. Regularly check the areas where they are most likely to gather for several days to make sure you have completely gotten rid of them all.
- Use a residual dust insecticide
If the problem persists or there are windows in the attic, inspect the area for live or dead flies and use a duster to apply residual dust insecticide. Apply the insecticide to spaces under floorboards, behind electrical outlets, around door frames or in any other voids where cluster flies may gather.
- Choose a spray insecticide
For quicker application, use a convenient residual spray insecticide for the areas mentioned above or anywhere else the flies gather. As with the other steps, check the areas daily for any lingering flies.