Why pigeons nest under rooftop panels, the bird laws that apply, how guards are fitted without harming the panels, and how to clean up droppings safely.
By the SolarCleaningRated team · Facts checked against the sources listed below on November 1, 2026. General information, not professional advice.
Utah State University Extension says rock pigeons nest on flat, covered surfaces such as sheltered cliff ledges, bridges and building surfaces, building a crude platform of twigs, grasses and sticks. The space under a rooftop array fits that description. The best-practice guide for solar operation and maintenance from the National Renewable Energy Laboratory (NREL) says bird populations are a source of soiling and leave nests that need to be removed, and recommends reducing open gaps between panels where birds can build nests.
The problem isn't only mess on the glass. NREL notes that where animals such as squirrels can reach a system's wiring, measures are needed to keep them away from it. It also offers some encouragement: birds are creatures of habit, and their behavior can be changed over time so they avoid your roof.
The law depends on the species. The US Fish and Wildlife Service's 2020 list of bird species to which the Migratory Bird Treaty Act does not apply includes the rock pigeon and the Eurasian collared-dove. The notice explains that the act applies only to species native to the United States or its territories. It also explains that species in bird families the treaties don't include, such as the house sparrow and the European starling, were left off the list, and that the only starlings that qualify for protection are those in the Japan treaty's annex that occur naturally in the United States or its territories.
Native birds are a different matter. The Fish and Wildlife Service says most bird nests are protected under the act and that it is illegal to destroy a nest with eggs or chicks in it; it is usually required to wait until the nest is inactive. Destroying an empty nest is not prohibited by the act on its own, but keeping a nest without a permit is, and permits to remove active nests are issued only in limited cases, such as a human health or safety concern. NREL suggests scheduling rooftop work and nest removal around the nesting season. Because it can be hard to tell whether eggs or chicks are present in some nests, the Fish and Wildlife Service recommends consulting an expert who can check. If you're unsure, ask your state wildlife agency.
Bird proofing for a rooftop array can combine two measures that NREL describes:
Utah State University Extension lists similar tools for pigeons in general: bird netting, closing openings, and deterrents such as spikes, coils and sloped surfaces.
How the guard attaches matters for the panels. Maxeon's manual says its modules are only certified for use when the factory frame is fully intact, and that creating additional mounting holes may damage the module. Ask how any guard attaches, and whether your panel maker accepts the method, before work starts. The installer shouldn't stand on the panels either: REC says never to stand on, walk on, lean on or apply pressure to its panels, and Maxeon says standing on modules may damage them and void the warranty.
Bird droppings can carry disease. A February 2026 safety bulletin from Los Angeles County's risk management office says three human diseases are known to be associated with pigeon droppings: histoplasmosis, cryptococcus and psittacosis. It explains that when droppings dry and are disturbed, particles become airborne and people may inhale them. Its precautions:
Keep the risk in proportion. The bulletin says everyday tasks such as cleaning windowsills are not expected to cause high exposure, and NIOSH says the fungus behind histoplasmosis is found mainly in central and eastern states, especially around the Ohio and Mississippi River valleys. A large build-up under an array is a different matter from a few spots on the glass.
NIOSH says the best way to prevent exposure is to stop droppings building up in the first place, for example by keeping birds out of buildings. Once the droppings are gone, clean the glass the way your panel maker allows. REC, for example, does not permit pressure washers on its panels; our cleaning guide has the details.
If the panels have to come off for a new roof later, the guard will need to come off too; our guide to removal and reinstall covers that job. Companies on this site that list bird and critter proofing are on our bird proofing page.
Rock pigeons are on the US Fish and Wildlife Service's list of birds to which the Migratory Bird Treaty Act does not apply. Native birds are different: destroying a nest with eggs or chicks is illegal, so identify the bird first and check state and local rules.
It can depend on how it attaches. Maxeon says its modules are only certified with the factory frame fully intact and that extra mounting holes may damage them. Ask your panel maker and installer before a guard is fitted.
NREL's best-practice guide recommends both for rooftop arrays: netting that seals the space under the panels all the way around, and spikes along the top edge to stop roosting. It adds that birds are creatures of habit whose behavior can be changed over time.
They can be. Los Angeles County's 2026 safety bulletin links pigeon droppings to histoplasmosis, cryptococcus and psittacosis, and recommends wet cleaning methods. For removing accumulated droppings, NIOSH tells employers to suppress dust and provide protective equipment such as a NIOSH-approved respirator.
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