Bird mites are miniscule, flattened parasites that feed on the blood of birds. The short lifecycle of bird mites, which contains five stages, enables bird mite populations to rapidly increase, sometimes into the tens of thousands in a single nest. The only life stage of bird mite that is visible to the naked eye is the adults which range in size from 0.7 to 1 mm in length. Coloration varies from translucent to reddish brown depending on how recently the mite has fed. Eggs, larvae and nymph stages cannot be seen without magnification. Bird mite development can occur in as little as five to twelve days under optimal conditions.
When populations become too high, young birds perish or leave the nest, bird mites typically evacuate the nest in search of an alternate host. During this time, bird mites may enter structures in large quantities. Although these mites are capable of biting humans, they are unable to reproduce without their species specific host. Bites to humans are encountered as the mites crawl along the skin conducting series of test bites seeking an avian host. Bird mites do NOT feed on human blood. Bites from bird mites are commonly described as a skin “prick” sensation. Bird mite bites commonly result in an itchy rash. As the mite bites, it injects saliva which can cause a localized reaction at the site of the bite. Misdiagnosis is not uncommon due to lack of presence of the mites upon examination by a physician or dermatologist.
Birds should be discouraged from nesting in or on structures. Disrupting nest building may encourage birds to build their nests elsewhere. Once nests are complete, many bird species are federally protected. Gaps large enough to allow entry by birds should be sealed or screened off to prevent access for nesting purposes. Due to their association with nesting season, bird mites are most abundant in late spring and early summer; however, as migratory birds leave their nests in the fall, occurrences may continue. Birds that nest year-round in warmer climates, such as pigeons, may also lead to bird mite encounters. When bird mites are detected within a structure, efforts should be made to locate and remove the source when possible. Thorough vacuuming on the interior will aid in decreasing activity. Insecticidal sprays on the exterior and heavily infested areas of the interior may be necessary to provide relief from the bite mite infestation. Although some species of bird mites can live a few weeks to several months without a blood meal, a majority survive only a matter of a few days inside of air-conditioned or dehumidified structures.