Understanding Cluster Flies and How to Get Rid of Them

Cluster flies, though less harmful than many other pests, can still cause significant annoyance and discomfort when they invade homes and buildings in large numbers. These flies are a common problem in the UK, particularly during the autumn and winter months, as they seek warm, sheltered areas to hibernate.

Summary

While they are not known to spread disease, their presence can be unsettling, and they can quickly become a nuisance. If you are dealing with cluster flies, it’s important to understand their behaviour and how to manage them effectively.

What Are Cluster Flies?

Cluster flies are larger than house flies, measuring 8-10mm, with dark grey bodies and golden hairs on their thorax. Unlike house flies, they do not breed indoors but spend most of their life cycle in soil, where their larvae parasitise earthworms. They become problematic during colder months when they seek warmth and shelter inside homes.

Cluster flies are not attracted to food or waste like house flies. The British Pest Control Association explain cluster flies enter homes through small cracks, vents, or roofline gaps as temperatures drop. They settle in dark, undisturbed areas like attics, wall cavities, and lofts, remaining dormant until spring.

On warmer winter days, they may emerge, often drawn to light sources like windows, becoming a noticeable nuisance. Their tendency to gather in large numbers, or ‘cluster’, makes them particularly troublesome for homeowners.

Signs of a Cluster Fly Infestation

Identifying a cluster fly problem early can help you prevent a full-scale infestation. Here are some common signs to watch out for:

• Large numbers of flies indoors: If you notice an unusual number of flies inside your home, especially around windows, attic spaces, or light fixtures, you may be dealing with cluster flies.
• Slow movement: Cluster flies are generally slower than house flies. You may observe them moving lethargically around your property.
• Dead flies in window frames: If you’re finding dead flies in window frames or around doors, it’s a likely sign that they’ve entered your home for hibernation.

Why Are Cluster Flies a Problem?

Though cluster flies do not pose a direct health risk, they can still be a considerable annoyance:

• Nuisance in numbers: Cluster flies can gather in large numbers, often filling attic spaces or wall cavities. Their presence can be alarming and frustrating, especially if they make their way into living areas.
• Odour: In large quantities, dead cluster flies can produce a musty smell, especially in enclosed spaces like lofts.
• Attracting other pests: Dead flies can attract other pests, such as beetles or mites, which can cause further problems.

How to Prevent and Control Cluster Flies

Once cluster flies have settled in, they can be difficult to eliminate completely without professional help. However, there are steps you can take to help prevent them from entering your property:

• Seal entry points: Inspect your property for gaps, cracks, or small openings that flies could use to enter. Pay particular attention to windows, doors, and rooflines, and ensure these areas are properly sealed.
• Install fly screens: Consider installing fly screens on windows and vents to prevent flies from entering while still allowing airflow.
• Vacuum up flies: If you notice flies in your living space, vacuuming them up is an easy and effective way to remove them.
• Professional treatments: For large-scale infestations or to prevent recurring problems, professional pest control treatments are the most effective solution.

The Benefits of Professional Pest Control

When it comes to dealing with cluster flies, professional pest control can be the best course of action. At Avon Pest Control we assess your property, identify entry points, and apply targeted treatments to eliminate the infestation and help prevent future problems. We use safe and effective methods to ensure that cluster flies are removed without harming your property or the environment.

Don’t wait until the infestation becomes overwhelming—contact Avon Pest Control today and take the first step toward a fly-free home.