Rodent Mites In Homes

Rodent Mites in Homes

This is a bothersome group of mites that parasitize poultry, wild birds, and rodents. When their normal host is not present they may also bite humans, causing discomfort and sometimes skin irritations. Fortunately, they do not reproduce on human blood, rarely transmit diseases or otherwise cause a health hazard to people. Although these mites are very small (about 1/32 inch long), they can be seen with the naked eye.

Bird and rodent mites and other types of mites found in homes can be difficult to distinguish but their control often requires that they are identified correctly. Any questionable samples should be examined by a specialist familiar with mite taxonomy.

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, Ornithonyssus bacoti, 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, Liponyssides sanguineus 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. This mite is of medical importance because it vectors Rickettsia akari, the rickettsial pox in humans. Fortunately, this disease is relatively rare in the United States and there have not been any known cases in Minnesota.

Another rodent mite which occasionally bites people is the spiny rat mite, Laelaps echidnina. 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

The easiest method to control bird or rodent mites that have entered your home is to physically remove them with a vacuum cleaner or wipe them up with a moist cloth. Mites are not automatically killed by a vacuum cleaner so freeze the bag to prevent the mites from crawling back out.

To prevent further problems with these mites, it is important to eliminate their hosts and any nests.

Rodent Mites
To eliminate mice and rats from the home, first locate the entrance/exit point used by the rodents to enter the building. Once located, the entrance/exit point must be completely blocked.

Second, remove all possible food sources by placing all pantry and cupboard foodstuffs into air-tight containers. Eliminate potential nesting sites by cleaning key areas such as closets, basements and storage areas.

Thirdly, trap rats and mice with kill traps, live traps and/or glueboards. Bait mouse traps with a mixture of peanut butter and rolled oats. Bait rat traps with meat products such as ham or beef. Arrange traps 10-15 ft apart placed perpendicular to walls, baseboards and rows of boxes. For more information on trapping rodents in the home, contact your county extension office.

University of Minnesota County Extension Service