Mites: Clover, Bird, Rodent & Dust

Clover mites mite

Clover mites are tiny, (smaller than a pinhead), about 1/30th of an inch long, and reddish-brown. Clover mites are pests not because they bit or cause disease, but simply because they can invade a structure in unbelievable numbers. They are often found indoors in late fall, winter, and early spring especially on the south and west sides of the structure. If crushed, these mites leave red stains on surfaces

Control:  Vacuuming will remove large numbers of mites, but care must be taken not to crush them. Treatment using a properly labeled, residual insecticide can be applied to windows, door sills and the outside of the structure

Bird Mites

Bird mites parasitize a wide variety of domestic and wild birds, including poultry, pigeons, starlings, sparrows and robins. These mites normally remain on birds or in bird nests throughout their life. Mite eggs are laid in nests or on feathers. Hatching occurs in two to three days and adults are seen about five days later if birds are present.

However, if a bird falls out of a nest and dies or a nest is abandoned, bird mites seek other hosts. These mites may enter homes, sometimes in large numbers to search for food when nests are on or in buildings. Although bird mites often bite people, circumstances have been described where they are found in large numbers but do not appear to annoy anyone.

Control:  Removal of dead birds, nesting material, closing of holes, ripped screens and other points of entry are effective means of prevention. Application of specifically labeled insecticides have proven effective in the control of these mites outside around windows, doors and other possible points of entry.

Rodent Mites

Rodent mites can be found in homes where rats or mice are abundant or where rodents have recently died. Several common rodent mites have been known to occasionally bite humans.

The tropical rat mite, is neither truly tropical nor exclusively feeds on rats. This mite can live for up to 10 days off its host and is capable of traveling great distances to find new food sources. In habitats where rodents have been killed, the mites will leave their dead hosts, congregate around heat sources, such as hot pipes and stoves and seek alternative food sources, including humans. The bite of these mites often causes tiny, clear blisters which is accompanied by a rash. However, they are not known to vector any human diseases.

The house mouse mite, has a worldwide distribution but is more common in the U.S. in the northeastern states. It is normally a nest dweller and only occurs on the host when feeding. It will attack humans if rodent hosts are not available.

Another rodent mite which occasionally bites people is the spiny rat mite. This is probably the most common mite occurring on Norway rats and roof rats in the U.S. It is not a known vector of pathogens.

Control:  Can most easily be accomplished by exclusion and elimination of the mouse and/or rat hosts. Insecticides, properly labeled, should be effective. Treat only those areas where the mite activity is known of suspected.

Dust Mites

It is an established fact that dust mites can be found in house dust all over the world. Dust mites are not insects but are more closely related to spiders and ticks. There are two common dust mites, the American house dust mite and the European house dust mite. Due to their very small size, these dust mites are not visible to the naked eye. They live in bedding, couches, carpet, stuffed toys and old clothing. Dust mites feed on the dead skin that falls off the bodies of humans and animals and on other organic material found where they live.

Though these mites live in many homes, only people who are allergic to them know they are there. Dust mites are second only to pollen in causing allergic reactions. When dust mites grow, they shed their skin. The shed skin and feces are what cause allergic reactions in people. Allergic reactions range from itchy noses and eyes to severe asthma attacks.

Dust mites do not live in air ducts in homes. Many people spend much time and money cleaning the air ducts to reduce dust mites. This is not necessary because dust mites need about 70 percent relative humidity or higher to live, and they need food. Areas where people spend much time, like a bed or a favorite plush chair, are prime sites for dust mites. The top part of mattresses containing fibrous material is a favorite place for dust mites during warm and humid times. The deeper parts of mattresses may provide protected areas for the dust mites during unfavorable conditions. Clothing is used by dust mites as a means of transportation from room to room or even from house to house.

Control: Dust mites can be difficult, time-consuming and expensive. For people who are extremely sensitive, the following measures should be taken:

  • Enclose mattresses, box springs and pillows in zippered allergen- and dust-proof covers.
  • Wash bedding materials, including pillow cases, sheets, blankets and mattress pads every other week in hot water (130 °F).
  • Eliminate or reduce fabric wall hangings such as tapestries or pennants.
  • Purchase stuffed toys that are machine washable.
  • Avoid using curtains, drapes or blinds on windows. Use plastic shades instead.
  • Remove carpeting from the bedroom of the allergic person and replace it with tile or wooden floors.
  • Replace upholstered furniture with wooden or plastic furniture.
  • Vacuum often with a vacuum cleaner provided with a high efficiency purifying air (HEPA) filtration system. Throw away vacuum bags after use because dust mites can leave the bag.

Installing HEPA filters on air conditioner or heater vents is not practical or necessary, and may actually increase mite problems. Remember, dust mites cannot survive on the dust in the ducts, and the small holes of the filters will force air out of vents at a higher velocity, stirring up more dust than without filters.

Complete elimination of dust mites is unlikely. Reducing populations is the only likely way to reduce allergens in the air. Reducing humidity in the home by using a dehumidifier may help reduce populations, but reducing humidity levels in microclimates, such as in bed fibers or carpet fibers, is impossible. Chemical control is not necessary, nor will it have a lasting effect on dust mite populations. Regular cleaning and vacuuming will have a greater impact