Mites (Acarina)
Mites are very small artropods that are barely visible to the naked eye. Anyone who identifies mites needs a good microscope. There are several species that feed on mammals or birds and that can occasionally invade homes and bite people and pets. They can bite people anywhere on their body and often where clothes constrict the body such as the waistline. They usually feed at night and when they hide, they will usually be near heat sources such as around hot water pipes, electrical fixtures and heating ducts.
There are three species that are fairly common in California.
Tropical rat mite (Ornithonyssus bacoti)
This mite feeds on rats but will bite people in rodent infested buildings or when rodents are poisoned and the mites leave the dead body. The bite can cause a painful irritation that can last for a few days, leaving red marks on the skin. When you scratch the bite area, you can possibly cause a secondary infection.
Northern fowl mite (Ornithonyssus sylviarum)
The northern fowl mite lives on some domestic birds as well as many species of wild birds. It is commonly found on chickens, sparrows and pigeons. When a bird dies or leaves the nest, the fowl mites will find their way inside a building and bite the inhabitants. This can be particularly troublesome of the birds are nesting in an attic.
Chicken mite (Dermanyssus gallinae)
This mite is commonly found on chickens but all feeds on other domestic and wild birds. They can actually migrate from a bird’s nest and invade a home. Along with chickens, they are commonly found on pigeons, sparrows and starlings, all species that will nest on buildings.
This mite is a parasite of chickens and many other domestic and wild birds. These mites can migrate from the nests of their hosts and invade home. Sparrows, starlings and pigeons are most often the wild birds responsible for household infestations.