Effective Bird Control Methods to Exclude Swallows from Nesting on Highway Structures

The swallow is a colonially breeding migratory bird that often nests on highway structures, bridges, and building eaves. Swallows are protected under the Migratory Bird Treaty Act of 1918, which strictly prohibits harming the birds or disturbing active nests containing eggs or hatchlings. This legal protection frequently causes significant construction and maintenance delays for transportation departments and commercial property owners. When nests are active, maintenance must halt until the young vacate. Once the nests are empty, they must be removed immediately, and effective bird control methods must be installed. Swallows naturally return to the exact same nesting sites year after year—and secondary pest birds will readily take over empty nests—making proactive exclusion essential.

Risks Associated with Swallow Nests

Swallows build mud nests in close proximity to human activity, quickly becoming a severe nuisance due to heavy fecal accumulation. Beyond the aesthetic damage, swallow droppings can foul machinery, create slick walkways, and pose biohazard risks by contaminating water sources. When mud nests eventually dry out and fall, they scatter debris and harbor dangerous parasites—including swallow bugs, fleas, ticks, and bird mites—that can infest surrounding structures and affect humans or domestic animals.

Bird Netting for Total Swallow Exclusion

Physical exclusion is the most effective and permanent strategy for preventing swallows from building nests. Exclusion systems deny birds access to protected angles beneath eaves, overhangs, and bridge girders. Heavy-duty bird netting creates an impenetrable barrier over these nesting zones. Secured using specialized perimeter cable, turnbuckles, or structural clips, the netting spans from the outer eave down to the wall face, eliminating shelter from the elements. Properly installed, professional netting is virtually invisible from the ground while completely barring swallow entry.

Deterrent Alternatives and Integrated Systems

For specific structural configurations where full netting spans are restricted, monofilament line systems can be installed across eave undersides. Spaced a few inches apart in parallel or zigzag patterns, these lines disrupt a swallow's flight path and prevent them from landing to plaster mud against the wall surface. While non-physical options like sonic audio deterrents can discourage birds by broadcasting predator and distress calls, physical exclusion barriers like bird netting remain the only guaranteed, total-exclusion solution for swallow control.

Bird B Gone is the world's largest manufacturer and distributor of commercial bird control products, providing legal, humane, and professional-grade solutions. For technical advice, netting design support, or regulatory compliance guidance, contact Bird B Gone at 800-392-6915.