Swallow nests attached to your home, porch, or barn can only be legally removed at certain times of year. Under federal law, disturbing a nest that contains eggs or chicks carries penalties of up to $15,000 and six months in jail. The timing of removal matters more than almost anything else, so understanding the rules before you grab a scraper is essential.
Why Swallow Nests Are Federally Protected
The Migratory Bird Treaty Act of 1918 makes it illegal to disturb the nest of any native bird without a permit. The law prohibits “taking” native birds, and that definition extends to killing, possessing feathers, destroying nests, or removing eggs. All North American swallow species, including barn swallows and cliff swallows, fall under this protection.
The U.S. Fish and Wildlife Service administers the act. While enforcement is uncommon for homeowners, the penalties are steep when applied. Equipment used in the process can also be seized. The law applies regardless of how inconvenient the nest location is. Maryland’s Department of Natural Resources specifically notes that nests cannot be removed even if they create piles of droppings underneath or are attached to buildings in high-traffic areas.
When Removal Is Legal
The key distinction is whether a nest is active or inactive. An active nest contains eggs, chicks, or is being used by nesting adults. An inactive nest is one the birds have abandoned after the breeding season ends. You can remove inactive nests without a permit.
In California, the Department of Fish and Game defines February 15 through September 1 as swallow nesting season. Completed nests during this window cannot be touched without a federal permit. Outside those dates, nests can be removed freely. Timing varies slightly by region and climate, but the general principle holds everywhere in the U.S.: once birds have left for the winter, the nests are fair game.
There is one important gray area. During the early nesting season, if swallows have started building but have not yet laid eggs, you can legally remove the partially built nest or install exclusion barriers. This is a narrow window, typically a few days, and it requires checking the nest carefully. Once eggs appear, you must wait until the chicks fledge and the birds leave.
Why You Shouldn’t Leave Old Nests in Place
Swallows are habitual nesters. They return to the same location year after year, and an existing nest acts as a beacon. If you leave old mud nests attached to your eaves or walls through winter, the same birds (or new ones) will reoccupy or build alongside them the following spring. Removing nests during the off-season is the single most effective way to discourage future nesting.
Old nests also harbor parasites. Cliff swallow nests are commonly infested with American swallow bugs, a close relative of bed bugs. Research from Colorado State University found an average of 269 to 297 swallow bugs per nest immediately after the birds abandoned them. These parasites survive in empty nests for months. After six months, adult bug populations dropped by 81 to 97 percent depending on the year, and after 12 months, numbers declined by over 90 percent. But a small percentage can survive even a full year without a host. When swallows return the next spring, bug populations explode again, and in the meantime, the parasites occasionally wander into nearby living spaces.
How to Remove a Swallow Nest Safely
Swallow nests are made of mud pellets mixed with grass, so they’re brittle once dry. Most can be scraped off with a putty knife or paint scraper. Here’s how to handle the process cleanly:
- Wear a dust mask and gloves. Dried bird droppings can contain fungal spores, and old nests may release dust containing parasite debris.
- Scrape the nest off completely. Don’t leave a partial mud base attached to the wall, as swallows will rebuild on top of it much faster than starting from scratch.
- Clean the surrounding area. Remove all droppings, feathers, and nesting material from below the site. A microbial cleaning solution designed for bird droppings works well for disinfecting the surface.
- Repaint or seal the surface. A fresh coat of paint over the cleaned area eliminates residual scent markers and creates a smoother surface that’s harder for mud to adhere to.
For nests on high eaves or under bridges, you may need a ladder or extension tools. If nests are on commercial buildings or large structures with dozens of nests, a pressure washer can remove dried mud efficiently during the off-season.
Preventing Swallows From Rebuilding
Removal alone often isn’t enough. Swallows are persistent, and if the location has good structural features (a sheltered overhang, a rough textured wall, proximity to water and open foraging areas), they’ll attempt to rebuild. Physical barriers installed before nesting season are the most reliable deterrent.
Bird netting stretched across eaves, overhangs, or the junction where a roof meets a wall blocks access to the surfaces swallows prefer. The netting needs to be taut and secured at all edges, since swallows will find gaps. Wire mesh serves the same purpose for smaller areas. For open entryways like barns or carports, overlapping vertical strips of vinyl plastic allow human access while discouraging birds from flying through.
Bird spikes installed along ledges, beams, and the tops of walls prevent swallows from landing and beginning a nest. These are widely available at hardware stores and attach with adhesive or screws. For smooth surfaces like painted wood or metal, simply maintaining the slick finish can help. Swallows need a rough or textured surface for their mud to grip, so glossy paint or aluminum sheeting under eaves makes nest-building difficult.
All of these barriers need to be in place before swallows arrive in spring. In most of the U.S., that means installation by late January or February. Once the birds have started building, your legal options narrow considerably.
Redirecting Swallows to a Better Location
If you want swallows on your property but not on your house, you can install artificial nest platforms or cups in a more suitable location like a barn, shed, or standalone post. Barn swallows readily adopt simple wooden shelves mounted to a vertical surface beneath an overhang. NestWatch, run by the Cornell Lab of Ornithology, offers free construction plans for DIY platforms. Ready-made clay and wooden nest cups are also available commercially.
The strategy works best when combined with exclusion from the unwanted location. Remove old nests from your porch, install netting to block rebuilding, and mount a nest platform 50 to 100 feet away in a sheltered spot. Swallows are adaptable and will often shift to the alternative site within the same season, especially if the platform mimics the sheltered overhang they prefer. Some homeowners report swallows building on a new shelf within a single day of installation.
Swallows eat enormous quantities of flying insects, so having them nearby is genuinely beneficial. The goal for most people isn’t eliminating swallows entirely but keeping nests off high-traffic areas where droppings, parasites, and noise become a problem.