Throughout the summer and early autumn cluster flies are 'field' flies and are not of any significance. However as the colder weather approaches they seek shelter, often in large numbers, in nooks and crannies of houses and other buildings. In the spring they emerge again

Cluster flies can be recognised by the short golden coloured hairs on the thorax. They pose no risk to human health and should not be taken as evidence of poor hygiene. However, they can pose a nuisance as they can accumulate in very large numbers to over winter in buildings.

Cluster flies often target a single house or one building in a row of similar buildings year after year. They are attracted to high, light-coloured walls especially if south facing.

The best method of control is to prevent the flies entering the premises in the first place. Preventing access into cavity walls e.g. sealing around service pipes and sealing around window and door frames and other obvious entry points can help to control any infestation. Also pay attention to any gaps at the eaves and fascia boards and to poor-fitting slates or tiles. Roof ventilation grills should be insect proof.

The Council does not offer treatment for cluster flies.

Cluster flies do not breed indoors so once they are inside they can be controlled relatively easily with a range of proprietary insecticides. Insecticides are dangerous so always make sure that you follow the instructions carefully and store them away from children and animals.

For an attic or roof space a smoke generator placed on a heatproof surface can be used. Make sure all water tanks and smoke alarms are covered and that no bats are in residence. It is an offence even to disturb bats. Ensure you inform the fire brigade especially in high density residential areas.

Private pest control companies will treat for cluster flies