What are Cluster Flies?

Many homeowners are familiar with the practice of swatting flies in the kitchen during the summer months. However, many people aren’t aware that there is another kind of fly flying around their homes – the cluster flies.

Cluster flies come to life in the fall when they fly to the warm-temperature homes in search of protection in over-wintering sites and may be found flying about inside, often in great numbers, during the winter. These flies are not reproducing within the home, but become active on warm days and crawl out of wall holes and attics in a confused attempt to find a way outside.

What do they look like? Adults are between 8 to 10 millimeters in length and have light and dark grey-checkered abdomens. The thorax of an adult cluster fly is covered in short, golden hairs and the wings overlap when the insect is resting. They are slightly larger and darker than the common houseflies and move more slothfully.

Do they pose a health risk?

Although some types of flies do present a risk of food contamination because of the way they breed and feed, cluster flies are not a health hazard, despite popular beliefs. However, cluster flies do become a nuisance in our homes and are parasites to our friendly earthworms.

It is also worth noting that cluster flies cause allergies if found in large numbers. They also attract secondary pests such as large beetles and provide food for mice in the attics and basements.

How do I prevent cluster flies from entering my home?

Clustering flies are known to enter the home through the smallest cracks near the doorway and window frames, but also through any other unsealed opening in the home. In order to prevent them from becoming a nuisance, the Government of Canada recommends that you:

  • Fill any cracks or crevices with caulking around doors, window frames, and other openings in the building structure;
  • Install insect screening over air vents in soffits.
  • Weather strip windows and doors;
  • Make sure that all screens fit properly and that there are no cracks or holes that would allow flies to enter your house;

How do you get rid of the cluster flies?

You can get rid of them by simply swatting them with a fly swatter. Be mindful of the fact that cluster flies do release unpleasant odours and may leave a stain when squashed. You can also try to release them outdoors or vacuum them up and dispose the vacuum bag.

About Any Pest:

If after reading this article, you find that cluster flies are still a nuisance, give us a call and we’ll help you get rid of the problem immediately. Any Pest offers environmentally safe, reliable, and superior pest control with the highest standards of professionalism and performance. The goal is to afford our customers with timely and effective treatments that protect their health and the quality of the environment they live in. When you call us, you can expect a quick response followed by a free, no obligations estimate by a qualified technician.