Attribution: Alan R Walker,[CC-BY-SA-3.0], via Wikimedia Commons
Bird mites are tiny; the size of a pin head or possibly smaller
Varies, usually dark, but possibly creamy white, depending on the species
A variety of mite species infest different types of birds and other animals. There are more species of mites that are not ectoparasites, but rather are pests of trees and other plants or live freely in the soil. Mites are one of the more difficult arthropods to identify, therefore requiring specimens be sent to a university with a qualified acarologist – an entomologist who studies mites. Knowing the type of mite involved is critical in determining the source of the infestation. (For example, mites occurring from the nests of rats or mice are also possible, though rare, in buildings.) On farms, mites that infest poultry sometimes become a problem in barns or can bite humans who work with the birds. More commonly, in homes and commercial buildings, mites that infest pest birds, such as pigeons and sparrows, may find their way into living spaces of homes. Some cases of mites biting humans in buildings have been reported.
Usually, one or more specimens are discovered wandering on a windowsill, on the floor, or possibly on a desk or table. Generally, such cases result from birds nesting in the attic, walls, or on the outside edge of the building roof. If the birds leave the nest, the mites will wander in search of a new host. Occasionally, however, bird activity within a commercial building (e.g., a church bell tower) that has been allowed to persist will cause an infestation of mites and other bird ectoparasites. They will wander indoors in search of new hosts. Like all mites, bird mites must remain on or very close to their hosts to survive, so they will be found in association with bird nests located on or within a building.
When wandering mites have been discovered in a building, the situation is best handled by an experienced professional. Correct identification by an experienced entomologist of the louse involved is key to determining the source of the mites. To control bird mites, the bird activity in or on the building must be eliminated or prevented and all nest materials removed. Areas where nests are located often require treatment to eliminate any wandering mites. Additionally, wall voids and other voids may need to be drilled and treated, depending on the situation.