Quick answer
The deer mouse is a wild rodent native to North America and the main reservoir of Sin Nombre virus, the hantavirus most often linked to HPS cases in the US. Not every deer mouse is infected, but because infected ones cannot be told apart by sight, public health authorities recommend reducing contact, sealing entry points and using damp cleaning in areas with activity.
Quick reference
| Species | Peromyscus maniculatus |
| Common name | Deer mouse |
| Main virus carried | Sin Nombre virus (SNV) |
| Disease | Hantavirus Pulmonary Syndrome (HPS) |
| Range in US | Most of the contiguous US, especially the West and rural areas |
| Typical habitat | Rural and peri-urban: cabins, sheds, barns, woodpiles, fields |
Where the risk is highest
CDC has documented Sin Nombre HPS cases in many states, more frequently in the Western US. Most exposures happen in rural and peri-domestic settings: cabins or sheds closed for months, barns, woodpiles and areas with visible rodent activity. The risk is not limited to one state: wherever the deer mouse is present, basic precautions are sensible.
Reducing contact with deer mice
- Seal gaps larger than ~6 mm in walls, foundations and around pipes.
- Store food and pet feed in airtight containers.
- Reduce nesting clutter: boxes, paper, old clothing.
- Keep wood, debris and brush away from walls.
- Before entering a long-closed cabin or shed, ventilate for at least 30 minutes.
For a detailed guide, see our hantavirus prevention or how to clean rodent droppings safely.
Frequently asked questions
What is the deer mouse?
The deer mouse (Peromyscus maniculatus) is a small native rodent widespread across most of the United States and Canada. It has a bicolour tail, white belly and large ears. It is the main reservoir of Sin Nombre virus, which causes Hantavirus Pulmonary Syndrome (HPS) in North America (CDC).
How does the deer mouse spread hantavirus?
Infected deer mice shed virus in urine, droppings and saliva. People can become infected by inhaling aerosolised particles when these excreta are disturbed — for example by sweeping in a cabin or shed — or, less commonly, through contaminated surfaces or bites.
Are all deer mice infected with hantavirus?
No. Only a fraction of deer mice in any given area carry Sin Nombre virus, and the prevalence varies by region and season. Because there is no easy way to tell which mice are infected, public health agencies recommend treating any rodent encounter with caution.
Where in the US is deer mouse hantavirus risk highest?
CDC surveillance has reported HPS cases across many states, with more frequent reporting in the Western US — including New Mexico, Arizona, Colorado, Utah, California and the Pacific Northwest. Rural and outdoor exposures (cabins, sheds, fields) drive most cases.
How do you keep deer mice out of the house?
Seal gaps larger than ~6 mm, store food (including pet food) in sealed containers, keep storage areas tidy, and reduce brush and wood piles near walls. CDC has detailed guidance on preventing rodent infestation; for established infestations, professional help is recommended.
Is the white-footed mouse the same as the deer mouse?
No. The white-footed mouse (Peromyscus leucopus) is a related species. Both can carry hantaviruses, but the deer mouse is the main reservoir for Sin Nombre virus in North America, and the white-footed mouse is associated with the New York virus, a related but rarer cause of HPS.
Medical disclaimer: This page is informational and does not replace professional medical advice. Biological and prevention information is drawn from public CDC documents.