Flies

What flies look like

The flies found in Ontario buildings run from about 2 mm to 16 mm long. House flies are dull grey with four dark stripes running down the thorax and reddish eyes. Cluster flies are a little larger, darker and slower, with short golden hairs that catch the light. Blow flies and bottle flies are stouter and metallic, in shades of green, blue or bronze. Fruit flies are tiny and tan with red eyes. Drain flies are small, fuzzy and moth like, and they rest with their wings held over the body. All adult flies have a single pair of wings, large compound eyes and sponging mouthparts. The young stage, the maggot, is pale, legless and tapered toward the head.

Signs you have flies

• Insects at the glass. Flies gather on sunny windows and patio doors, buzzing against the pane and dropping to the sill.
• Autumn and spring clusters. Cluster flies pile into attics, window frames and quiet upstairs rooms, then wake on warm days.
• Dark specks. Small brown or black spots on light fixtures, ceilings, mirrors and pale walls are fly droppings and regurgitation marks.
• Maggots. Pale grubs in a green bin, under a fridge, in a floor drain or in a forgotten bag of potatoes mean breeding on site.
• A sour or sweet smell. A strong odour with heavy fly traffic in one room often means a dead rodent or bird in a wall or ceiling.
• Drain activity. Small flies drifting up from a rarely used sink, shower or floor drain point to organic build up in the pipe.

A few flies in July is ordinary. A steady supply usually means something nearby is breeding them.

Why flies show up around Ottawa and Toronto properties

Flies follow food, moisture and warmth, and cities offer all three. Green bins, garbage rooms, dumpsters behind restaurants and unrinsed recycling create ideal breeding material through the warm months. Pet waste on lawns, backyard compost, manure on rural properties near Ottawa and spilled fruit in kitchens all add to the supply. Warehouses and food businesses hold heat and odour that draw flies in through loading doors. Cluster flies behave differently. They develop in soil, feeding on earthworms, then move toward sun warmed walls in late summer and press into siding gaps, soffits and attic vents to overwinter. That is why homes on the edge of fields, parks and ravines in the National Capital Region and across the GTA see them year after year.

Are flies dangerous?

Flies do not bite or sting, but they are not harmless either. House flies, blow flies and bottle flies feed on garbage, manure and carrion, then land on counters, dishes and food. They carry bacteria on their feet and mouthparts and can transfer organisms that cause stomach illness. That makes them a real concern in kitchens, daycares, food plants and restaurants, where a visible fly problem can also affect an inspection. Cluster flies and drain flies do not spread disease in the same way. They are mainly a nuisance, although large numbers of dead cluster flies in an attic can attract carpet beetles. Fly larvae in stored food make it unfit to use. The practical risk is contamination and complaints rather than injury.

How to keep flies away

• Keep green bins and garbage cans closed, rinse them often and line them so liquid does not pool in the bottom.
• Repair torn screens, fit door sweeps and check that vents and soffits are screened so overwintering flies cannot get in.
• Clean drains and grease traps on a schedule so the film that small flies breed in never builds up.
• Pick up pet waste daily, turn compost regularly and keep it well away from doors and windows.
• Store fruit in the fridge once it ripens, wipe up spills under appliances and empty recycling before it ferments.
• Switch exterior lighting to fixtures aimed away from entrances so flying insects are not drawn to the door.

Removing the breeding material does more than any spray can.

How GO! Pest Control handles flies

• Inspection. We identify the species first, then trace it back to the source, whether that is a drain, a bin room, a dead animal in a void or sunny siding on the west wall.
• Treatment. We apply licensed products where they fit the species and the site, including exterior residual applications for cluster flies and targeted treatment of resting surfaces indoors.
• Proofing. We point out and can address the gaps that let flies in, from failed screens and vent covers to loose soffit and door seals.
• Follow-up. We return to check the result, reassess activity and adjust the approach if the source turns out to be somewhere else.
• Advice. We give you a plain sanitation and monitoring plan, which matters most for restaurants, food handling sites and multi unit buildings.

We are licensed, insured and bonded, and we work in homes, apartments, condos and businesses across the Toronto GTA, Ottawa and Hamilton.

Common questions about flies