Cluster Fly FAQ
How to get rid of cluster flies
Cluster flies look for somewhere to hibernate when the temperatures start to drop, they often take refuge in lost spaces, wall cavities, cracks and crevices, which can make them hard to get to, and hard to know if you have treated them all if you are carrying out the pest control yourself.
Where do cluster flies come from?
Cluster flies are more common in houses close to open spaces, fields, and farmland. During the summer cluster flies live and breed in these fields, and don’t cause any problems as they feed organic matter, their larvae live in the soil feed on earthworms.
What attracts cluster flies?
Cluster flies are attracted to spaces that will provide a place for warm and undisturbed hibernation over winter. Presence of these flies is not a sign of poor hygiene, as the only attraction will be a safe place to hibernate.
Are cluster flies dangerous?
These flies do not pose a direct threat to human health unlike the house fly. Cluster flies lay their eggs in earthworms, not food, and do not spread disease or bacteria. They don’t bite, and are not considered harmful to humans.
How long do cluster flies stay?
As the temperature starts to drop in late summer early autumn, cluster flies head to somewhere warm. This can often be the side of your house where the sun is shining. Once the temperatures drop even more, the flies will then seek shelter indoors. They invade in large numbers, and gain their name from the way they cluster around window frames and in loft spaces.
They will remain in hibernation until warmer weather arrives in the spring. It is not uncommon for a warmer winters day to bring them out early, and they will head for south facing windows where it is warm.
How to stop cluster flies coming back
How to stop cluster flies returning
Whilst blocking up obvious entrance points and ensuring windows and doors are sealed will help, it is almost impossible to completely prevent cluster flies from gaining access to your property, as they can use very small cracks and crevices as an entry point.
Cluster flies leave a scent each year, which will bring back more of them each year. The only way to prevent this from happening is to treat the problem each year until no more flies are returning to the property.
Cluster fly prevention
As with all pest problems, prevention is better than cure. Although little can be done to stop them from getting in, professional treatments can prevent the infestation from getting worse and returning the following year. It is advisable to have treatments every year until the cluster flies are no longer present.
Life cycle of cluster flies