top of page

FLIES - Info, Advice & Help

Seasonal Prevention and Control Tips for Cluster Flies in Ontario Properties

Quick Facts About Cluster Flies

  • Common across Ontario, especially in rural or farmland areas.

  • Often mistaken for house flies, but cluster flies are slower and less erratic.

  • They seek shelter in attics, walls, and voids during fall to overwinter indoors.

  • Do not breed indoors or spread disease, but can appear in large numbers.

Common Signs of a Cluster Fly Issue

  • Flies gathering around sunny windows, especially in late winter or early spring.

  • Buzzing or sluggish flies emerging from light fixtures, wall gaps, or attics.

  • Visible clusters forming on exterior walls or windows in the fall.

  • Repeated sightings in upper floors or attic spaces.

Prevention Tips

  • Seal cracks, vents, and gaps around windows, rooflines, and soffits.

  • Install fine mesh screens over attic vents and exhausts.

  • Keep window screens in good repair and use caulking to close entry points.

  • Vacuum up flies as needed; avoid using fly sprays inside walls or voids.

When to Call a Professional

Fly.webp

  • You see cluster flies appearing indoors year after year.

  • DIY sealing hasn’t stopped seasonal infestations.

  • Large numbers are found in attics, upper floors, or around windows.

  • You want preventative fall treatments for long-term control.

How PPM Pest Control Can Help

  • Thorough inspection of your property’s upper structure and entry points.

  • Timed fall exterior treatments to prevent overwintering.

  • Eco-conscious insecticide application tailored to your building type.

  • Ongoing support for cottages, homes, and businesses across Ontario.

bottom of page