The familiar Daddy-Longlegs. A large mosquito-like fly with a long narrow body, which enters buildings in late summer. Harmless, although unpleasant in appearance. Its larva is the “leather- jacket” which damages grass roots.
Any household fly killer aerosol will knockdown and kill Crane Flies.
For a heavy Crane Fly infestation, we would recommend you contact professional pest control company, preferably a member of the BPCA to administer a professional treatment to solve the problem. A trained professional will have the technical knowledge and access to a range of professional use products and equipment which are not available to the public.