Bird Mites in the House After a Nest Is Gone

What are bird mites?

They are tiny parasites that feed on the blood of birds. University of Minnesota Extension describes them as about one thirty-second of an inch long, with eight legs, generally brownish or grayish and darker after feeding, and visible to the naked eye. The entomologist who runs the University of Wisconsin-Madison Insect Diagnostic Lab says the best description is walking flakes of pepper, and that their nearly constant movement gives them away.

Several species go by the name. Minnesota Extension says the most common are the northern fowl mite and the chicken mite, that they live on a wide variety of domestic and wild birds including poultry, pigeons, starlings, sparrows and robins, and that they normally remain on birds or in bird nests throughout their lives. Eggs are laid in nests or on feathers and hatch in two to three days.

Why do they come indoors after a nest is abandoned or removed?

Because their food just left. Minnesota Extension explains that if a bird falls out of a nest and dies, or a nest is abandoned, the mites look for other hosts, and when nests are on or in buildings they may enter homes while searching. The Wisconsin lab notes that mites are most noticeable when young birds have just left the nest and the mites wander looking for a blood meal.

Iowa State University Extension puts the timing in late spring, when baby birds are leaving the nest, and says the wandering mites may be found anywhere in a home but are most abundant near nests built on or in the building. So the pattern is predictable: a nest in a soffit, a vent, a wall void or over a window, then mites on the nearest sill, ceiling or bed a few days after the birds go.

Which nests cause most of the trouble?

The ones attached to the house. Iowa State says sparrows, starlings and pigeons are the birds most often associated with bird mite problems in buildings, which matches the three species that nest inside structures in western Montana. The Wisconsin lab's list of typical sites is worth checking against your own house: under a deck, on a patio light fixture, in a gutter, in a damaged soffit, or in a shrub just outside a bedroom window.

Poultry count too. Minnesota Extension calls bird mites parasites of poultry as well as wild birds, so a backyard coop against a garage wall, or wild birds nesting in the coop, can be the source. It adds that mites can also arrive on pet birds such as parrots or canaries. Our guides to birds in dryer and bathroom vents and birds in attics and soffits cover the nest sites that put mites closest to living space.

How long do bird mites live without birds?

Not long. Minnesota Extension says northern fowl mites complete their life cycle on the host but can live in the environment without one for two to three weeks, and that without a meal of bird blood they die. The Wisconsin entomologist reads the literature the same way: off their bird hosts the common species may survive a matter of weeks under the most ideal conditions, and in most cases conditions are so dry that survival is limited to a few days at best, especially in an air-conditioned home.

This is the fact that matters most, because it contradicts much of what circulates online. The Wisconsin lab writes that it has had to console clients who read that the mites would infest them, their homes and their vehicles indefinitely. Minnesota Extension is plain about it: because they cannot reproduce on human blood, bird mites cannot create an ongoing infestation in a home.

Do bird mites bite people, and are they dangerous?

They can bite, and that is the extent of it according to the extension sources. Minnesota Extension says bird mites can bite people as they search for hosts, that the bites are generally annoying, that reactions vary and may be more painful for some people, and that bird mites have not been found to transmit any diseases to people. Iowa State says they can bite humans but are not a health threat, and that they do not harm stored food, plants or furnishings. It also says they will probably infest pet birds.

We are not a medical source. Skin reactions have many causes, and itching that continues well after a nest is gone, or any bite that looks infected, is a question for a clinician. If the cause is uncertain, getting the specimen identified helps both of you.

Is it really bird mites?

Confirm before treating. Minnesota Extension warns that bird mites and other mites found in homes are difficult to tell apart, that correct identification is necessary for effective control, and that a specialist should be consulted if you need help. Several other kinds of mites turn up indoors and have nothing to do with birds.

Collect a few on clear tape or in a small sealed container and take them to your county Extension office, which can route a sample for identification. Meanwhile, look for the nest. Mites near one window with a nest in the soffit directly above is strong circumstantial evidence. Mites with no nest anywhere on the building suggests a different culprit.

How do you get rid of them?

Remove the source, then mop up the stragglers. The Wisconsin lab calls removing the nest once the birds have left the single most important step and says that, like flipping a switch, mite activity typically drops off within a day or two. Indoors, Minnesota Extension says physical removal is the most effective measure: vacuum the mites or wipe them up with a moist cloth. Vacuuming does not kill them, so freeze or discard the bag. The Wisconsin lab adds that dry air is the mites' biggest threat, so running air conditioning or a dehumidifier may speed things along.

On chemicals, Minnesota Extension says an insecticide applied around the outside of the home at windows, doors and other entry points helps keep mites out, and Iowa State describes residual sprays near the nest site and in cracks and crevices, always following the label. Both say hiring a pest management professional is an option. HJ does not apply insecticides. Our part is the nest, the debris and the opening, and a licensed pest control operator handles any treatment.

When can the nest come out?

This is where bird law and mite control meet. Minnesota Extension's guidance is not to disturb nests if eggs or young of federally protected songbirds are present, that once the nesting season is over the nest may be removed, and that pigeons, starlings and house sparrows are not federally protected, so their nests may be removed at any time. Montana Fish, Wildlife & Parks likewise states that starlings are not protected by federal or state law. For any other bird, the U.S. Fish and Wildlife Service treats a nest with viable eggs or nestlings as in use and places the responsibility on whoever removes it to be sure it is inactive.

So a robin's nest on a porch light stays until the young fledge, and you manage the mites indoors in the meantime. A starling nest in a vent can go now. Our Montana nest removal law guide explains the distinction, and lawful removal is part of our bird nest removal service. When handling any old nest, the Internet Center for Wildlife Damage Management advises wearing gloves and bagging the material to avoid contact with nest mites.

Keeping them from coming back

Mites return when birds return. Once the nest is out and the area is clean, close the opening so the site cannot be reused: mesh over the vent or soffit gap, a repaired panel, or a barrier on the ledge or light fixture. Remove dead birds promptly, as Minnesota Extension advises, and check the same spots each spring before nesting begins.

Closing nest sites on a building is what our bird mitigation service does, and dropping removal is covered under bird dropping cleanup. More on birds in and on buildings 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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