Deer Mice
Order:
Rodentia
Family: Muridae
Species: Peromyscus spp.
Deer mice occur throughout the United States. Although the genus of the deer mouse is rather large and each species has its own common name, all members of the genus are often referred to as either deer mice or white-footed mice.
The most common and widely distributed species is P. maniculatus, the true deer mouse. This species gained national notoriety last summer when public health officials determined that it was the principal rodent species associated with the transmission of the hantavirus. This virus is transmitted through the inhalation of particulate matter contaminated by the droppings and urine of infected mice. Disease mortality in humans is approximately 60 percent.
Identification
While differentiating the species of the Peromyscus genus is extremely difficult and should be left to experts, several characteristics - particularly coloration - clearly distinguish deer mice from house mice. The house mouse is a solid color. In contrast, the deer mouse has a bi-colored appearance: the upper portion of the body and tail is medium- to dark-brown, while the underside of the tail, feet and stomach area is white. In addition, the eyes, ears and body of a deer mouse are slightly larger than those of the house mouse.
Biology and Habits
Deer mice are active all year round. They produce three or four litters, each having three to six young; thus, populations can build up rapidly. They normally produce their largest litters in the spring, depending on climatic conditions. They are nocturnal and are rarely seen in their outdoor habitat. They often construct nests in hollow logs and tree stumps, under logs and stones, and occasionally in bird nests and shallow burrows. Deer mice are rarely a major problem in residential areas; however, housing in rural and agricultural areas may have more of a problem.
In the fall and winter, deer mice frequently enter homes, garages and outbuildings, and occasionally campers and other infrequently used vehicles. Once in these areas they can cause significant damage to furnishings and stored materials as they search for food and construct their nests. Their typical diet consists of nuts, seeds, berries and insects. They often store food in their nests for the winter months.
Control
The best solution for problems with deer mice is exclusion. Seal entry holes with 1/4 inch (6mm) hardware cloth, sheet metal or metal wool. Pay particular attention to any hole approximately the diameter of a pencil. In some situations, perimeter trapping may prevent a population from becoming established indoors. In addition, avoid storing pet foods and other food products in accessible areas such as garages, and eliminate any water sources that may also prove attractive.
Due to increased concern over the hantavirus, deer mouse populations in structures should be eliminated as quickly as possible.
(Courtesy of the National Pest Control Association.)