Damage to Structures
The principal problem caused by white-footed and deer mice is their tendency to enter homes, cabins, and other structures that are not rodentproof. Here they build nests, store food, and can cause considerable damage to upholstered furniture, mattresses, clothing, paper, or other materials that they find suitable for their nest-building activities. Nests, droppings, and other signs left by these mice are similar to those of house mice. White-footed and deer mice have a greater tendency to cache food supplies, such as acorns, seeds, or nuts, than do house mice. White-footed and deer mice are uncommon in urban or suburban residential areas unless there is considerable open space (fields, parks) nearby.
Damage to Landscapes and Crops
Both white-footed and deer mice occasionally dig up and consume newly planted seeds in gardens, flowerbeds, and field borders. Their excellent sense of smell makes them highly efficient at locating and digging up buried seed. Formerly, much reforestation was attempted by direct seeding of clear-cut areas, but seed predation by deer mice and white-footed mice, and by other rodents and birds, caused frequent failure in the regeneration. For this reason, to reestablish Douglas fir and other commercial timber species today, it is often necessary to hand-plant seedlings, despite the increased expense of this method.
Human Health and Safety
In mid-1993, the deer mouse (P. maniculatus) was first implicated as a potential reservoir of a type of hantavirus responsible for an adult respiratory distress syndrome, leading to several deaths in the Four Corners area of the US. Subsequent isolations of the virus thought responsible for this illness have been made from several Western states. According to the Centers for Disease Control and Prevention, deer mice, white-footed mice, rice rats, and cotton rats are rodents that carry hantavirus. Since surveillance began in 1993, 833 cases have been reported in the US as of the end of 2020.
The source of the disease is through human contact with urine, feces, or saliva from infected rodents. To reduce your chance of getting sick when cleaning an area that has rodent urine, droppings, dead rodents, and nesting materials:
- Use a preferred disinfectant: a general-purpose household disinfectant (has “disinfectant” on the label) or a fresh mixture of 1 part household bleach to 9 parts water.
- Wear rubber or plastic gloves.
- Do not vacuum or sweep as viral particles may become air-borne and inhaled.
Heavy rodent infestations may require protective googles, a respirator, and other personal protective equipment. For detailed information on proper clean-up, see CDC Clean-up.