Jeffrey Hahn, Asst. Extension Entomologist
Bird mites, especially the northern fowl mite, Ornithonyssus sylviarum, have been a common problem this summer entering homes and biting people. Bird mites are a major pest of chickens but will also parasitize many wild birds, such as pigeons, sparrows, starlings, and robins and are associated with nests that are built on or in homes and other buildings. Bird mites normally remain on birds and in nests throughout their lives where populations can grow to the tens of thousands.
If the mite populations become too large, or if the birds abandon their nest or die, the mites will move off en masse and look for an alternate food source and commonly enter homes. Bird mites are flat and the size of a pin-head, about 1/32 inch long. Although, they are very small, people can just barely see these mites. It also helps to see them when there are a lot of them around and they are moving.
When northern fowl mites encounter people they will taste test us, although they do not survive on human blood. Their bites are annoying but fortunately bird mites do not transmit any diseases to people. They also do not infest people and you will not accidently transport them and allow them to infest other buildings, like bed bugs. Northen fowl mites do not survive off their hosts for more than a few weeks.
If you have a bird mite problem, it is important to find the bird nest that is the source of the infestation. If the nest is empty, remove it, place it in a garbage bag, and throw it away. If the nest is occupied by pigeons, starlings, or house sparrows, i.e. birds that are not federally protected, you can remove their nests even though there are birds still in it. However, if eggs or young are found in nests of any song birds, they are federally protected and can not be disturbed as long as the nest is occupied. Once the nesting season is over and only adults remain, you may remove the nest, as long you do not harm the birds.
You can use an insecticide application to help reduce the number of bird mites migrating indoors. Pyrethroids, such as permethrin, bifenthrin, cyluthrin, deltamethrin are effective. Treat outside around windows, doors, and other possible points of entry. If you can not treat an outside area without harming an occupied nest, do not spray. Leave the nest alone until it is abandoned; then you can spray the house if mites are still a problem.
Once bird mites are inside your home, remove them with a vacuum or wipe them up with a cloth and rubbing alcohol. Bird mites are also susceptible to dry conditions. Running your air conditioner or a fan can help reduce humidity and kill bird mites. Bird mites should go away on their own within several weeks.