Birds in the Attic, Soffit or Wall: What to Do

How do you find where they are getting in?

Watch before you climb. Stand back from the house in the first hour of daylight, when adults are making feeding trips, and note exactly where the bird disappears. Most entries are at a joint: where a soffit panel meets the fascia, at a gable vent with a torn screen, where a roof valley meets the eave, behind a loose trim board, or through a hole a woodpecker started.

Then look for the supporting evidence. White streaking below one spot, nesting material poking out, staining on the soffit, and noise concentrated in one room all point to the same opening. On log and cedar-sided homes in the Bitterroot, check the gaps where log ends, knee braces and roof framing meet, since those joints open up as timber shrinks. Check the whole roofline before deciding there is only one entry.

Which bird is it?

Three species account for most nests inside buildings. European starlings are the classic cavity user: Montana Fish, Wildlife & Parks says they exploit gaps around roofs and walls, and the Montana Field Guide lists cavity-like openings in buildings among their preferred nest sites. House sparrows, the Field Guide notes, often nest in enclosed spaces and can raise up to four clutches between early April and mid-September. Pigeons need a bigger opening; the Internet Center for Wildlife Damage Management lists lofts, steeples and attics among the places they inhabit, with a nest that is a crude platform of sticks, twigs and grasses.

Then there are the birds that make the hole. Montana FWP notes that woodpeckers excavate cavities for nesting and roosting, that cedar siding is among the most vulnerable, and that even unfinished holes may be adequate for starlings or house sparrows, so holes of all sizes should be repaired promptly. Our guide to northern flicker and woodpecker damage covers that. If you cannot tell what you have, a photo of the bird or the nest material is usually enough for us to identify it.

Could it be bats instead?

Often, yes, and the answer changes the plan. Montana FWP says bats roosting in a building can go unnoticed for years, that they can squeeze through cracks as small as one inch wide, and that their droppings may be found on the attic floor or staining a ceiling or siding. The test FWP suggests is to watch a corner of the building starting 30 minutes before dusk and continuing for one hour. Birds are active by day and quiet at night. Bats leave at dusk.

FWP's guidance for bats is exclusion through a one-way exit, never between May and August when young may be present, with fall as the best time. Bats found in living space where someone was sleeping raise a rabies question that belongs with your local health department. Bat work is not part of our bird service, but we will tell you if that is what the evidence shows.

What are the rules if the nest is active?

They depend entirely on the species, which is why identification comes first. Montana FWP states that starlings are not protected by federal or state law and that pigeons are not protected in Montana, and University of Minnesota Extension notes that pigeons, starlings and house sparrows are not federally protected and their nests may be removed at any time.

Any other bird should be treated as protected. The U.S. Fish and Wildlife Service defines an in-use nest as one with viable eggs or nestlings, says destroying one requires federal authorization, and recommends doing work outside the nesting season to reduce risk. FWP says the same about woodpeckers: once they have eggs or young, it is illegal to remove them from the nest or to scare the adults away. In practice that means waiting until the young have fledged, then closing the opening. The rules are set out in our Montana nest removal law guide.

How do you get a trapped bird out?

A bird loose in an attic, garage or room is usually lost, not nesting. The Internet Center for Wildlife Damage Management's advice is to restrict the area where the bird can fly by closing doors and, because birds tend to fly toward light, to darken the area except for the exit. In a room, that means closing interior doors, drawing the blinds, opening one window or exterior door wide, and stepping back. In an attic, open the access to daylight if there is a safe route out, and give it time.

Do not chase it. An exhausted bird that can be picked up may be injured, and Montana FWP says not to touch an animal that is clearly injured or in distress but to call the Montana WILD Wildlife Rehabilitation Center for advice at 406-444-9942. FWP also points out that it is illegal to possess and care for a live animal taken from the wild, and that fledglings on the ground are usually being fed by their parents and are almost always best left alone.

When and how should the opening be sealed?

Seal only when you are sure nothing is inside. Closing an opening over live birds traps them in the wall, which is cruel, unlawful for protected species, and the source of the smell and fly problems people call about weeks later. Watch the opening for a couple of mornings, check for sound, and if a nest of an unprotected species is being removed, take it out completely first.

Then use material a bird cannot pull apart. Montana FWP recommends sealing starling entrances with hardware cloth or metal flashing and warns that plastic netting and window screen will not hold. Utah State University Extension, working with USDA Wildlife Services, advises closing all openings larger than one inch to keep starlings out. Attic and soffit vents still have to breathe, so they get mesh, not a solid patch. Rotted fascia or failed soffit panels need a carpenter or roofer first, since mesh over rot does not last. Our bird netting and exclusion page describes how we close openings.

What about the insulation and droppings left behind?

A single season's nest in a soffit bay leaves a compact mess. Several years of starlings or pigeons in an attic leave droppings worked into the insulation, old nests stacked on each other, and sometimes dead birds. Matted, soiled insulation no longer insulates well, and the material should not be stirred up dry. The National Institute for Occupational Safety and Health advises wetting droppings before removal, avoiding shoveling or sweeping dry, dusty material, and leaving large accumulations to a professional cleanup company.

We do not repeat the method here. Our bird dropping cleanup page explains how we handle it, and bird dropping health risks explains why. Replacing insulation is an insulation contractor's job once the space is clean and sealed. Expect the nest to have carried parasites too, covered in our guide to bird mites.

How do you keep them from coming back?

By treating the whole roofline, not the one hole. Birds that lose a nest site look for the next gap along the same eave, so the inspection should cover every soffit joint, gable vent, ridge end and utility penetration, plus dryer and bathroom vents. Look again each March before nesting starts, and after any wind or snow load that could have opened a panel.

That roofline survey is the first step of our bird mitigation service, and the rest of the series is in the Montana Bird Control Guide.

Call HJ Property Care & Tree Service at (406) 215-7319 or request a bird assessment and we will identify the species, the access points, and what will actually stop them.

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