Three mouse species in Maine are known for infesting homes and buildings where they pose a medical threat to humans. These mouse species include the house mouse, the deer mouse and the white-footed mouse. The house mouse is easily the most common home-invading mouse species in Maine, and the entire US. Unlike deer mice and white-footed mice, house mice prefer indoor as opposed to outdoor environments, and they invade homes throughout the year. Once indoors, house mice establish nesting sites within enclosed areas where they damage a variety of structural materials, and worst of all, their excrement quickly becomes abundant within largely inaccessible locations, mainly wall voids. While house mice are the most damaging and economically significant of all rodent pests in Maine, they are not necessarily the most medically hazardous.

House mice can enter homes by squeezing through tiny holes on exterior walls, or by slipping beneath door gaps, and in some cases, they manage to access roofs where they crawl through attic vents, pipes, or gaps around utility cables. House mice enjoy gnawing on a variety of materials, including plaster, wood, insulation, food packages, and electrical wiring. In fact, housefires have resulted from house mice gnawing on electrical wires in wall voids. Worst of all, house mice invade cupboards and pantries where they chew their way into food packages, especially cereal boxes. House mice leave traces of salvia, urine and excrement within the food packages they damage, and these bodily substances contain a variety of disease-causing microorganisms, including Salmonella.

Hantavirus pulmonary syndrome (HPS) is one of the deadliest diseases spread by mice in the US, and while this disease is mainly a threat to residents of the southwestern states, at least one individual has contracted HPS in Maine. This case was reported back in 2011, and several local news outlets in Maine mistakenly stated that the house mouse was responsible for transmitting the disease. However, only four rodent species in the US are known to transmit HPS, and the house mouse is not one of them. The white-footed mouse and the deer mouse, both of which invade homes in Maine during the colder months, are known to spread HPS, but it is believed that only the white-footed mouse spreads HPS in the northeast. Luckily for residents of Maine, HPS is not considered a major public health threat in the state, and white-footed mice tend to invade homes in rural regions as opposed to urban and suburban homes.

Have you heard that house mice spread hantavirus in Maine?