Dermanyssus gallinae is the scientific name for the common red mite, a species of parasitic mites that feeds by sucking on the blood of birds. These mites can affect any species of birds, including household pets. Poultry, however, especially chickens and turkeys, appear to be the parasites' favorite prey. Due to their believed preference for poultry, they may sometimes be called the poultry red mite or chicken mite. Sometimes the term red mite might also be used to refer to other species of mites that are red in appearance, such as the European red mite.
Red mites are ectoparasites, meaning they do not live inside their host but feed by attaching to their skin. In fact, these mites spend most of their time separate from the host and can actually survive for months without feeding. Chicken mites tend to hide in bird nests or along cracks and crevices within chicken coops, birdcages, and other structures. If red mites are in the household, mites may get into the carpeting, furniture, and bedding, practically any dark area where they can avoid sunlight. At nighttime, these nocturnal mites come out to suck blood from the host, and then they hide again, mating and laying eggs.
Typically measuring between 0.02 to 0.04 of an inch (approximately 0.5 to 1 millimeters) in length, red mites may be barely visible to the naked eye as moving specs of dirt. Most of the time, however, they may not be identifiable without magnification, as they generally appear opaque until after feeding. Once engorged with blood, these mites will appear bright red in appearance.
Mites usually feed for less than an hour at a time and normally only need to feed several times a week. The blood that they ingest is required for reproduction, and within 24 hours of the first feeding an adult female red mite is ready to lay eggs. The life cycle for red mites, which goes from egg to adulthood, can be completed in less than one week, meaning populations of red mites can build up rapidly when control measures are not used.
Birds being bitten by a few red mites might appear restless and may be seen trying to rub or itch irritations on the skin. When the infestation is large, however, weight loss may occur, and birds might become anemic from the large amount of blood lost through mite bites. In chickens, a drop in egg production may also occur. For young birds, the infestation may be fatal. Although not considered likely, it is also probable that these mites may transmit diseases to their avian hosts.
One way of determining if an infestation of red mites is occurring is to hang a piece of white cloth or a sheet over a cage at night. The next morning, the material can be inspected for mites. As they are likely to have recently fed, they should appear as small red specks. Mite droppings may also be identifiable as small black specks.
Although it is not possible for these biting mites to reproduce when feeding on non-avian hosts, they can feed off mammals, including humans. Usually this is only a problem for poultry farmers or others who work with and live near infested birds. When mites feed off on nesting birds, however, they may become more of a nuisance. Once these nesting birds mature and leave the nest, these mites may seek out alternate hosts by invading nearby homes or other buildings.
As red mites are hearty and tend to adapt to practically any environment, red mite elimination and control should be done as soon as mites are identified. Usually the birds being affected and their environment will both need treatment. Once the birds are removed, poultry houses and cages often need to be rigorously cleaned and disinfected. A steam cleaner or pressure washer may also be useful for cleaning into any crevices or cracks where mites are hiding and making certain they are washed away. Use of miticides, pesticides specifically designed to kill mites, can also be used for treatment and regular prevention once the mites are eradicated.