If you have a cluster fly infestation, you must take action. Treatment is very seasonal & is time-sensitive as they enter your home in the fall & only exit spring. They go dormant as they are just looking to survive the winter season. A cluster fly isn’t a fly house. Although both insects look fairly similar, they have very different characteristics.  In order to recognize the signs of an infestation, you must know what you’re looking for.

Cluster Flies 101

When dealing with cluster flies chances are you have multiple different flies invading at the same time. A cluster fly is bigger than a housefly. An average house fly is about 3 mm, and a cluster fly is around 7 mm. In terms of color, a cluster fly is black. When they are young they have silver stripes on their wings. House flies are gray, and they have black stripes. When flying, they move slower than a housefly, and when they land, their wings overlap. Cluster flies like to form clusters on windows or in any location that gets natural sunlight.

The Signs of an Infestation

  • During a Chinook or a warm winter day they may emerge as wall voids will heat up flies and force reanimation (but usually only small percentage of Harbouring population).
  • On a hot day in the late fall, swarms will often form clusters on the side of a home moments before they invade it.
  • When they are grouped together, they make a lot of noise. If there is a cluster in your ceiling or attic, you’ll hear buzzing sounds.
  • Cluster flies lay eggs outdoors in the spring. If you have a spring infestation, you’ll find many flies waiting to go outside on your doors and windows.
  • Many will leave small dark spots on various windows and walls. These stains are not poisonous.
  • When cluster flies are disturbed, they produce a very strange odour.
  • If there are dead cluster flies in your wall voids, they will attract larder beetles.

Defend Your Home with Canned Insecticide Sprays

One way to get rid of cluster flies is by using an aerosol insecticide that contains pyrethrin. It will kill the flies on contact. Pyrethrin comes from a natural plant extract, so it’s safe to use indoors.

Capture Cluster Flies with a Mini Vac

When a swarm invades home, their goal is to eventually hibernate. Before hibernation begins, they become very sluggish and slow. This is an excellent time to extract them with a mini vacuum.

Catch Cluster Flies with UV Light Traps

UV light traps are effective because cluster flies are attracted to light. A nine to 12-watt light trap can catch many flies in a 600 to 800 square-foot space.

How Prevent Cluster Flies

They can fit through any cracks and crevices on walls and gaps around door frames. If your doors or windows have cracks, carefully fill them with caulk. To strengthen your defences, spray a good detailed residual insecticide application on the side of your home. In the spring treat the exterior as you want to target flies exiting the structure. In the fall target the exterior & interior, it will deter flies away for a few days. Assassin Pest Solution has more than 30 years of pest control experience. Contact us for a free assessment and leave your cluster fly pest control needs safely in the hands of the professionals.
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