Barn swallow nests can only be legally removed when they are inactive and empty. Under the Migratory Bird Treaty Act of 1918, destroying a nest that is in use is a federal crime, and that protection kicks in earlier than most people expect: once a bird begins spending time in a nest, even if the nest is not yet complete, removing it is illegal. This means timing and prevention are everything.
What the Law Actually Prohibits
The Migratory Bird Treaty Act makes it a federal offense to hunt, kill, capture, sell, or otherwise harm migratory birds, and that includes destroying active nests. Barn swallows are a protected migratory species. The key legal distinction is between an old, empty nest and one that a bird has started using. Old nests from previous seasons with no bird activity can be knocked down at any time. Mud deposits at the very beginning of construction, before a bird has settled in, can also be removed. But once a swallow starts spending time on or in the structure, you have to wait until it’s empty again.
Trapping or shooting barn swallows is also illegal. Attempting to scare them away from an active nest is generally ineffective anyway.
Depredation Permits for Active Nests
If barn swallows are causing genuine damage to property, posing a health risk, or creating a safety hazard (such as near airport runways), the U.S. Fish & Wildlife Service offers a depredation permit that can authorize removal of active nests. Getting one is not simple. You must first document that you tried nonlethal measures like scare devices or habitat modifications, providing receipts, invoices, or photos as proof. You also need to contact USDA Wildlife Services (866-487-3297) to determine if your situation warrants a permit. They may require a site visit before completing the required review form.
The application fee is $100 for businesses and commercial properties, or $50 for individuals dealing with damage to a personal residence. Government agencies are exempt from the fee. The process involves multiple forms and supporting documentation, so it’s not a quick fix for a single nest on a porch. It exists primarily for larger-scale or safety-critical situations.
How to Remove an Inactive Nest
Empty nests from a previous season can be knocked down with a pole, scraped off with a putty knife, or washed off with a hose. Barn swallows build with mud pellets, so the nests tend to be firmly attached to walls, eaves, and rafters, but they break apart without too much effort once dry. Remove all the debris and clean the surface underneath.
This step matters because barn swallows readily reuse old nests. Leaving last year’s nest in place is essentially an open invitation for the same pair, or a new one, to move back in. Removing it during the off-season (late fall or winter) is your best window.
Health Risks From Nests and Droppings
Bird nests can harbor mites, particularly northern fowl mites and chicken mites, which live on a wide range of wild birds. When the birds leave and the nest goes dormant, those mites sometimes migrate into nearby living spaces looking for a new host. They can bite people, causing itchy, irritating welts, though the severity varies from person to person. The good news is that bird mites cannot reproduce on human blood and have not been found to transmit diseases to people.
When removing a nest or cleaning droppings, wear gloves and a dust mask. Droppings can contain fungal spores that become airborne when disturbed. Wet the area first to reduce dust, then scrub and dispose of the material in a sealed bag.
Preventing Nests Before They Start
Prevention is the most practical strategy, and the time to act is before nesting season begins in spring. Once swallows claim a spot, your options shrink dramatically.
- Netting or wire mesh: Cover likely nesting areas, particularly eaves, the junction where a roof meets a wall, and rafters in open structures like barns or carports. The mesh should be tight enough that birds can’t slip through or attach mud to the surface behind it.
- Bird spikes and barriers: Commercial spike strips installed along ledges and beams prevent birds from landing and building. These work well on narrow horizontal surfaces.
- Vinyl strip curtains: For open entryways like barn doors or loading docks, overlapping vertical strips of vinyl plastic can block access while still allowing people and equipment to pass through.
- Interrupting early construction: If you notice fresh mud deposits appearing on a wall or beam, knock them down daily before a bird begins occupying the site. Consistency matters. If you skip a few days and a bird settles in, you’ve lost your legal window. Continue daily removal until the birds abandon the location.
Combining methods works best. Removing old nests in winter, then installing physical barriers before spring, addresses both the attraction of an existing site and the possibility of new construction nearby.
Living With an Active Nest
If swallows have already nested and you missed the prevention window, you’re legally committed to waiting it out. The typical barn swallow nesting cycle, from egg-laying through fledging, runs roughly six weeks. Some pairs raise two broods in a season, which can extend your timeline into late summer.
To manage the mess in the meantime, install a dropping board a couple of feet below the nest. A simple shelf, a piece of plywood, or even sturdy cardboard suspended by wire or screws will catch most of the droppings and food debris. Keep the board narrow enough that it doesn’t block the birds’ flight path in and out of the nest. Clean the board regularly to prevent mite and insect buildup in the accumulated waste.
If possible, install any boards or catchers before the breeding season at sites where you know birds have nested before. Approaching an active nest with large chicks is risky because older chicks can jump out prematurely, which often kills them. Quick, minimal-disturbance installation is the goal if birds are already present.
Once the nest is empty for the season, remove it promptly, clean the site, and install deterrents before the next spring to break the cycle.