Professional Cluster Fly Control Services in the UK

Cluster flies, often mistaken for houseflies, become a seasonal nuisance when they enter homes and buildings in large numbers to hibernate during the colder months. These sluggish fliers gather in roof spaces, wall cavities, and other secluded areas, often reappearing on sunny winter days near windows. While they pose no direct harm, their presence can be distressing due to odours, stains, and sheer volume.

Understanding the Cluster Fly Lifecycle

• Eggs: Laid in soil, particularly in areas with earthworms—their larval host.
• Larvae: Parasitic to earthworms, completing development underground.
• Adults: Emerge in late summer and seek overwintering sites such as attics and wall voids.

Where Are Cluster Flies Found?

• Loft spaces, roof voids, and attics
• Behind walls or within cavity insulation
• Around window frames in upstairs rooms
• Shared overwintering sites with ladybirds

Why Do Cluster Flies Infest Properties?

As temperatures drop in late summer and early autumn, adult cluster flies seek shelter in warm, undisturbed spaces to hibernate. Properties with easy access through roof vents, eaves, or gaps in walls are especially vulnerable. They are attracted to the warmth and shelter provided by lofts and wall cavities, often entering in large numbers year after year if not treated.

Are Cluster Flies Dangerous?

No — cluster flies are not known to transmit disease and are not considered harmful to humans or pets. However, their presence in large numbers can result in unpleasant odours, staining of walls and windows, and general discomfort, especially when they become active during warm spells in winter months.

How to Control and Prevent Cluster Flies

• Seal entry points such as gaps around windows, vents, and roof edges
• Treat known harbourage areas with residual insecticides before winter
• Install fine mesh over roof vents and loft air bricks
• Use electronic fly killers fitted with cluster fly trays to trap large infestations
• Arrange annual treatments if re-infestation occurs seasonally

Professional Help for Persistent Infestations

Cluster fly problems can be hard to eliminate due to their overwintering behaviour and preferred hiding places. At Shire Pest Solutions, we offer expert treatments and preventative strategies tailored to your property. Whether it’s a one-off infestation or a recurring seasonal issue, our team can inspect, treat, and protect your home or business effectively.

Do Cluster Flies Carry Diseases?

No — cluster flies are generally harmless and do not carry disease. Unlike houseflies, they do not feed or breed inside homes. Their nuisance value stems from their tendency to invade in large numbers and cause visible staining. Nonetheless, managing their presence improves hygiene, comfort, and peace of mind during colder months.