Deer Mouse

What Is a Deer Mouse?

One of the most abundant organisms in North America, deer mice can be found in nearly any woodland ecosystem and are prominent throughout the continent. Nocturnal and prone to staying well-hidden in their natural habitat, the pests are rarely spotted by humans. The rodents frequently travel from one nest to another, which means large infestations typically do not occur. However, deer mice carry serious diseases, as well as other vectors like fleas and ticks, that threaten the health and wellbeing of humans and pets.

What Do They Look Like?

deer mouse

Adult deer mice grow as long as 6 to 8 inches from the tip of the nose to the end of the tail.  The common name of the deer mouse actually comes from the coloration of the rodent, which resembles a white-tailed deer. Deer mice are traditionally brown on the back and white on the underbelly, legs, and tail.

Characteristics: In addition to their notably large eyes and ears, deer mice have long, thin tails and hind legs that are longer than their forelegs.

What is the difference between a deer mouse and house mouse?

Where Do They Live?

Distributed throughout North America, deer mice are found in woodlands, grasslands, alpine regions, agricultural fields, brush lands, and in manmade structures. The pests can survive at any altitude and also live in mountainous areas and on tropical islands.

What Do They Eat?

Omnivorous and adaptable, deer mice tend to be opportunistic eaters when they inhabit manmade homes and buildings. In nature, the pests target adult insects and their larvae, various invertebrates, seeds, fruits, grains, fungi, flowers, and nuts.

Life Cycle

Female deer mice give birth to as many as 11 litters in one year. Each litter consists of anywhere from one to nine pups who reach sexual maturity after five or six weeks. The deer mouse gestation period lasts about 24 days, and females can become pregnant again shortly after giving birth.

Young deer mice are born tiny, hairless, and blind and depend on their mother for survival during their first month of life. The pests typically live a year in the wild but can survive for two or three years in captivity.

Detection

  • May notice deer mouse droppings around the house.
  • Look for nests made of twigs, leaves, roots, and other fibrous materials.
  • Check for the greasy stains that deer mice leave on walls, windows, and other surfaces.

Problems Caused by Deer Mice

Damage

Typically, deer mice do not remain in one place long enough to cause significant property damage. However, the pests will damage upholstered furniture, mattresses, clothing, paper, and various other materials to make their nests.

Disease

Deer mouse saliva and waste carry many viruses and bacteria harmful to people. Two of the most dangerous deer mouse diseases are hantavirus and salmonellosis.

Hantavirus

Deer mouse urine and droppings are the main vector for hantavirus. Touching or even breathing in these waste particles can spread the disease. Although rare, rodent bites can lead to infection as well. Homeowners risk exposure when they clean out storage areas where deer mice nest.

Once infected, victims can develop Hantavirus Pulmonary Syndrome. The illness begins with flu-like symptoms and may lead to severe respiratory issues. If untreated, this deer mouse disease can be fatal.

Salmonellosis

Also transmitted through waste, this deer mouse disease often passes to humans through food. Eating items contaminated by Salmonella bacteria in pest droppings is the easiest way for the ailment to spread. Most cases clear up in about a week, but acute symptoms may require hospital care.

In addition, deer mice spread Lyme disease, which causes rashes, joint paint, and neurological issues, and Hantavirus, which causes symptoms that may include fever, aches and pains, and gastrointestinal problems.

Signs of Deer Mice in the Home

Deer mice generally keep to themselves. As a result, the most common signs of a deer mouse infestation rarely include actual sightings of the rodents.

Droppings

People are more likely to encounter droppings around the home if deer mice are present.

Identifying Deer Mouse Droppings

mouse feces
Mouse droppings

Deer mouse droppings are easy to distinguish from other types of rodent poop because of its size and shape. Deer mouse waste is similar to dark-colored grains of rice. On the other hand, rats often leave behind blunt-ended excrement about the size of raisins.

Problems and Dangers

Known carriers of hantavirus, deer mice pass the disease through their saliva, urine, and feces. This makes coming across the pests’ waste dangerous for homeowners.

Accidental ingestion and inhalation can occur when deer mouse droppings start to dry up, creating dust in the air. The first symptoms of hantavirus include fever, fatigue, and muscle aches.

Our mouse infestation guide can help you deal with the droppings.

Nests

Additionally, as the pests frequently abandon old nests to create new ones, homeowners may stumble upon empty deer mouse nests made from twigs and leaves, with moss, dried grass, rabbit fur, feathers, or a similar material on the inside for insulation.

Learn how to get rid of a mouse infestation.