Cluster Fly Treatment
Are You Being Bothered by Flies?
If the answer is yes, call us today on 0800 0283 703
We can have a local technician with you within 24 hours to deal with the problem.
While Cluster Flies can be a great nuisance they dont normally represent a health hazard. However, they can:
- Produce a rather sickly smell when clustered in large numbers.
- Be upsetting and unnerving if disturbed during hibernation
- Be unsightly when flying or when found in and around window frames.
All our technicians are fully trained so that you are in safe hands when employing our services.
We can offer you an effective one off treatment programme or a longer term prevention plan.
To find out more about how we can help you please call us on 0800 0283 703.
Alternatively complete our online contact form for a free survey and detailed quotation.
CALL YOUR LOCAL TECHNICIAN
Service + Protection = Peace of Mind
Cluster Fly – Pollenia rudis

Often confused with the common House Fly, Cluster Flies are roughly the same size.
However, they fly somewhat slower than the House Fly and usually fly toward windows on the warm side of a structure. When at rest, their wings overlap almost completely.
Cluster Flies breed in the ground outside of buildings during the warm weather (late Spring into early Summer) using earthworms as a food source for the immature larvae (maggots).
The flies later pupate (go into the cocoon stage), then hatch as adult flies.
In temperate areas, often in late August, these flies begins to migrate indoors finding any small cracks or crevices that permit entry into structures. These may include areas around window frames, door frames or eaves.
Entry tends to be on the same, warm, sunny side (often the southern or western exposure) of the structure as the flies later emerge from.
During the Autumn, Winter or Spring months, these flies may emerge, particularly on warm, sunny days. The flies appear at windows buzzing and “clustering” around those areas to the dismay of the occupants.
This fly can become a problem in virtually any structure and they have, on occasion, been a problem in sensitive areas such as hospitals, where they are especially unwelcome.
Why Control Cluster Flies?
Whilst Cluster flies can be a great nuisance they do not normally represent any health risk. However they can :
Produce a rather sickly smell when clustered in large numbers
Be upsetting or unnerving if disturbed during hibernation
Be unsightly when flying or when found in and around window frames
Cluster flies may congregate and die in wall spaces, voids and lofts etc and then attract other insects eg the larder beetle
The flies can contaminate foodstuff and spread diseases
Method of Control
We control Cluster Flies by treating the adult resting sites and harbourages.
They may have flown a considerable distance from their original breeding site, so we do not attempt to control their larvae.
Typically, the treatment will include a spray with an insecticide to affected window frames and the interiors of sash-window cases.
We will also inspect the roof spaces and, where appropriate and safe to do so, use a smoke generator to eradicate any residing cluster flies.
Electric Fly Killers, hanging in attics or loft spaces, are particularly effective in providing continuos control.