Rarely a problem in domestic situations, but frequently an issue in commercial premises such as bakeries and warehouses. Sparrows can enter buildings through tiny gaps and, once in, are very difficult to remove.
Remedy
Proofing with nets and blocking of entry holes are usually the preferred options used by professionals, subject to an appropriate licence having been issued.
See also Birds
Having problems with sparrows?
For any bird work, we would strongly recommend contacting a professional pest control company, preferably a member of the BPCA. They are trained in bird control and will have access to a range of professional use products and tools which are not available to the public.
Search for your local BPCA member