Measures taken to prevent swallows from building nests around a home include the use of a non-toxic bird repellent or installing physical barriers. Bird netting or special brackets are often used to keep swallows at bay. Any preventative steps regarding swallows must conform to U.S. environmental protection laws.
One way to prevent swallows from building nests on a porch is to apply a commercially made bird repellent on areas where birds may nest. Bird repellents come in gel or liquid form and contain ingredients that smell and taste bad to the swallows. These repellents create a transparent layer on surfaces, making those areas uncomfortable for the birds. Bird repellents are biodegradable and non-toxic to humans and pets.
Bird netting is one type of barrier that is commonly used. Bird netting is draped or attached to eaves or other structures where birds usually nest. Chicken wire can be used instead of bird netting.
Some professional pest removal services install slick brackets, which resemble crown molding. The brackets are painted to blend into the home's exterior. Returning swallows are unable to roost in areas with brackets. It may be required to remove existing swallow nests before installing barriers. Legally, a swallow's nest may be removed only when there are no eggs or live birds using the nest.