In all regions of the country, if new eggs or nestlings are present in the nests, a permit authorizing nest removal or the use of exclusion techniques is required. A permit will be issued only for very compelling concerns for human health and safety. Some examples are concerns for aircraft safety from a nesting colony at an airport or potential food contamination from a colony over a loading area at a food processing center. In most cases a permit for lethal control will not be issued for swallows nesting on a residence or other buildings causing aesthetic damage. You will be referred to a district biologist who will assess the problem and make control recommendations.
Timing is critical.
It usually takes 10 to 14 days to obtain a permit so you must plan ahead if a problem is expected. It is not advisable to wait until nest building begins to apply for a permit, because swallows build their nests and lay eggs in a short time. For those regions that require a permit, if a swallow problem has been experienced in the past at a site and is expected to reoccur, then apply for a permit in advance of the birds' return. In areas where a permit is required, the nest removal method will be specified by the permit. In California, old nests or nests under construction may be washed down with water or knocked down with a pole.