For many people, signs of spring are plants peeking out from underneath a thin layer of snow, robins singing in budding trees, or big, bumbling flies buzzing and banging up against windows. At first glance they resemble houseflies; however, they are larger, darker and slower in their movements. These flies are commonly referred to as cluster flies and can be abundant in houses with large lawns or those backing onto open parks along with farm fields and wooded areas. The name “cluster fly” is derived from their habit of entering a house in the fall and gathering in clusters that may emit a sickly, sweetish odour if disturbed.

Cluster flies hibernate in secluded areas of houses, such as in wall voids, attics, closets and empty rooms. They are a particular nuisance as they leave stains on the walls and curtains. If the flies die in the wall voids they may attract larder beetles, which will feed on the dead flies and then migrate to other areas of the house. In the spring, the sluggish cluster flies will migrate from their hibernating areas to living spaces and gather on windows as they are attracted to light.

So why are cluster flies in my house?

In the fall, cluster flies seek to overwinter in manmade structures to protect themselves from the cold. You’ll see them on sun-warmed sides of your house, dancing about on inner walls and lumbering around in attic spaces. When spring arrives, they flood back out into your common areas just trying to get back outside.

Why do cluster flies stay in my house?

They enter the home through the tiniest cervices, soffits, roof vents, siding, and   around door and window frames, but also through any other small unsealed opening’s. Once inside, while it is cold they will become dormant, but on very sunny days, even in winter they may become active and sometimes will be found flying around your home. These are common entry points for cluster flies.

But this is spring. What do I do about these bugs now?

If you decide to go at them with a fly swatter, which would take you hours, you should understand why these pests swarm. The reason for this behavior is that these flies release a scent that draws them all together in one spot. Knowing about this pheromone scent can help you get rid of this pest. To reduce cluster flies in your home or on your property, call a pest control company. Greenshield Pest Control has a Home Protection Plan Program where we come to YOUR home and complete an Interior and Exterior spring and fall treatment. For the Exterior treatment we use residual control products to spray all around your home. With the Interior being completed by a attic or void areas fogging treatment, along with around your window frames!

To find out more on how Greenshield Pest Control can help you keep flies and other pests out of your home all year round.

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