The deer mouse is the most abundant and widely distributed mouse in North America. It is found around homes and buildings in rural and semi-rural areas, but it is not normally found in cities. It can be found in forests and grasslands, meadows and marshes.

The deer mouse is often confused with the field mouse, white-footed mouse and the white footed deer mouse. The deer mouse has white feet, a white underside and brownish upper surface, and a bi-coloured tail. There is a definite separation between the white belly and darker upper surface. Their eyes and ears are larger than those of the house mouse, and they are considered to be more attractive than house mice. They prefer to eat seeds, however, they will also eat insects, slugs, snails, spiders and millipedes.

Because of their feeding habits, they may be considered beneficial. Unfortunately, they are also strongly associated with the Hantavirus which causes Hantavirus Pulmonary Syndrome (HPS), and their chewing habits are the cause of structural damage in homes and other structures. It is estimated that 25% of fires which have unknown causes are caused by rodents chewing electrical wires. Chewing telephone and computer cables can do more than just cause structural damage. One mouse is capable of bringing down entire businesses. Their control, particularly indoors, is essential.

Questions & Answers

How long does a deer mouse live, and how often does it reproduce?

The deer mouse will live for up to 8 years in captivity, however, because of lack of food, predation and disease, they usually live for 2 to 24 months. The young will reach sexual maturity at 7 to 8 weeks and females will have litters of 3 to 5, 2 to 4 times per year. Their productive success is determined by food availability. When food is abundant, they are successful at reproduction and numbers can become quite high. If food is scarce, they are unsuccessful and numbers will be low.

How does a deer mouse enter my home?

The deer mouse will enter a home or other structure through any opening, providing at it is greater than 0.6 cm. (1/4 in.). Openings may be below ground level, at ground level, or on roofs. They are capable of climbing trees, bricks, downspouts and they have tremendous jumping abilities. Consequently, they are capable of gaining access to roofs where they can enter through chimneys and roof vents.
How do I know if I have a deer mouse infestation?
If you live in a rural or semi-rural area, near a field, forest or other undeveloped area, there is a possibility that deer mice could enter your home.

They tend to be quite noisy as they will drum their paws at a speed so great that they sound like buzzing insects or humming electrical wires. They will build nests and stockpile food (mostly seeds and nuts) in out-of-the-way areas. Finding these are strong indicators of a deer mouse infestation.

Chewing damage and droppings are not good indicators. All mice will chew and produce droppings. Their runways are not distinct as many of them are made by other small mammals, so they are also poor indicators.

Where will a deer mouse build its nest?

Outside, a deer mouse will build its nests around fence posts, in tree hollows, woodpiles, old and abandoned bird and squirrel nests and beneath decks. Inside the home, nests will be built in basements, attics, storage area, wall voids, sill plates, structural corners and other tight spaces which offer shelter.
What does a deer mouse nest look like?
The deer mouse will build its nest from almost any material which it can find. Outside, nests are built with grasses and small sticks. They are domed and have only one entrance. They look like small piles. Indoors, the nests will look the same except they will be made from paper, string, cloth, insulation or any other materials which may be found inside the building.

If I see many nests, do I have many deer mice?

No. One deer mouse will have several nests. They have a habit of fouling their own nest and, consequently, are forced to leave it and build or find another.

What can I do to prevent deer mice from entering my home?

Prevention requires a combination of strategies. The deer mouse, like any other mouse, requires an opening into the structure, so it is important to seal off every hole, crack and gap. Doors should be equipped with tight fitting doorsweeps or weather-stripping, and should be kept closed during their active time (early evening to pre-dawn).
Weed control goes hand-in-hand with rodent control. Making the area surrounding your structure unattractive to the mice will keep them away.

Keeping your property clean and orderly will limit nesting sites and materials. All potential sources of food should eliminated. Dried foods should be stored sound, rodent-proof containers. Grass seed should be kept off of the ground, also in sound, rodent-proof containers.

Because of the risk of Hantavirus transmission, and potential structural and electrical damage it is very important to rodent-proof your residence or business and eliminate existing deer mouse infestations.

Please contact your nearest Abell Pest Control office for assistance.