Deer Mouse

Category:

Actual Size: 5” to 8” long including the tail

Characteristics: Gray to reddish-brown with white feet and underbelly.

Habitat: Build nests in trees or beneath logs outdoors; inside, often found in basements or attics.

Habits: 

  • Prefer to nest in dark outdoor areas.
  • Sometimes referred to as field mice or white-footed mice.
  • Transmits the potentially fatal Hantavirus Pulmonary Syndrome.

Deer Mice in Puerto Rico

Deer mice, often referred to as field mice or white-footed mice, are found throughout the nation including right here in the San Juan region. Deer mice prefer woodlands, but they are also established in desert areas. Most often found outdoors in rural areas, deer mice rarely invade residential properties. These rodents are a common problem in agricultural areas, and will sometimes look for shelter in homes over winter. Their true danger lies in the fact that they are common carriers of hantavirus. They feed at dusk and dawn, and tend to prefer insects, seeds, nuts, and berries.

Deer Mouse Habitat

Deer mice are nocturnal and spend their days in cup-shaped nests made of stems, leaves and fibrous materials. Nests are lined with feathers or shredded cloth and can be found in tree hollows, fence posts, abandoned squirrel and bird nests, and the underside of logs and rocks. In homes, deer mice construct nests in low activity areas such as basements, attics, garages and crawl spaces. Deer mice do not hibernate, and may invade homes during winter months seeking shelter in storage boxes, wall voids, and upholstered furniture.

Deer Mouse Behaviors, Threats or Dangers

Throughout most of the year, deer mice nest in outdoor areas that are quiet, dark, and undisturbed. When the weather gets colder during winter, deer mice tend to invade homes, garages, sheds, and sometimes even vehicles. When they get indoors, they are often found in basements or attics. The biggest threat of deer mice is that they are able to transmit the dangerous—and potentially fatal—hantavirus. This disease is often transmitted through contact with mouse carcasses, or by breathing in air-borne urine droplets from infected deer mice.

Due to the risk of exposure to hantavirus, trapping and removing mice should be performed by a licensed rodent control company.