Cluster flies are a returning pest.
They establish in the right environment and regardless of any new development, new house, remedial work, extension...they know the area and will return.
They appear twice a year - Spring and Autumn.
In Spring, when the sun starts warming the roofs of buildings they will be reactivated by the warmth, where they will have been in 'stasis' over the winter. They will then go off and breed.
Their offspring will come out in the Autumn and head back back to their ancestral home - your property.
They are attracted to light coloured buildings and a pheromone that will be on the building which unfortunately cannot be washed off.
If you have them you don't need to 'just put up with them'. They feed on decaying matter and generally unwanted guests so give us a call and we can help.