House Mouse

What is House Mouse?

One of the more common pests found in the United States, the house mouse frequently takes up residence in homes and other manmade structures. When the rodents invade homes, they consume and contaminate foodstuffs and wreak havoc on structures and property. House mice also spread diseases such as salmonellosis and are known carriers of other vectors, such as fleas and lice.

What Do They Look Like?

house mouse

Size: The house mouse ranges in size from 5 to 7 inches long, including the 3- to 4-inch tail.

Color: House mouse fur varies in color from light brown to black, while the underbelly typically appears beige. Interestingly, the closer a house mouse lives in relation to humans, the darker the fur becomes.

Characteristics: The tail of the house mouse bears some fur and has circular rows of scales. House mice thrive in various environments and are found in and around both homes and businesses, contaminating food meant for humans and domesticated animals alike. Adult mice reproduce rapidly and tend to live around a year in the wild.

house mouse image
house mouse

Where Do They Live?

Native to Central Asia, house mice found their way to North America on ships going from Europe to the New World. Distributed across the world, the rodents can be found anywhere humans are.

What Do They Eat?

House mice are omnivores with a diet focused on seeds, roots, leaves, and stems. The pests also feed on insects and other sources of meat when available. When house mice live with or near humans, they become opportune feeders that will eat any available foodstuff or household item, including glue, soap, and paper.

Life Cycle

Female house mice can produce between 5 and 10 litters per year, with each litter containing anywhere from 5 to 12 young. Pregnancy lasts up to 21 days until the young are born furless, blind, and helpless. Newborn house mice develop quickly, maturing to adulthood in just 6 to 10 weeks. Females are ready to mate about a month after birth, while most males reach sexual maturity two months after being born. The average lifespan of a house mouse falls around one year in the wild and up to three years in captivity.


  • Fecal pellets, urine stains, and grease trails may indicate a house mouse infestation.
  • Look for gnawing damage and tracks along baseboards.
  • Listen for audible signs, such as squeaking and scratching in walls, ceilings, attics, and crawlspaces.

Problems Caused by House Mice

House mice contribute to a variety of issues in and around the home. The rodents can spread diseases that cause varying levels of sickness in humans, as well as contaminate food with their droppings.

These may be transmitted in several ways:

  • Ingesting waste left by foraging mice in pantry food.
  • Not washing hands thoroughly when cleaning up after rodents.
  • Breathing in particles of the pests’ dried droppings.

Some of these diseases have serious symptoms, so mouse infestations shouldn’t be ignored.

Additionally, the pests are voracious feeders that consume large quantities of stored food and crops. House mice can also damage woodwork and building structures, as well as furniture, wiring, and even clothing, if left unchecked.

Signs of Infestation


The most prevalent sign of a house mouse infestation is either seeing the rodents themselves or finding their droppings around the home.

Identifying House Mouse Droppings

house mouse poop
house mouse droppings


Secretive and able to survive with little food and water, rodents are usually first discovered by finding their waste. House mice leave behind 50 to 75 droppings a day, readily making their presence known.

House mouse feces is easy to distinguish from other pests’ poop, as it is only about one-fourth of an inch in length. These dark brown to black pellets have tapered ends.

Problems Associated with Mouse Waste

Locating mice is key to getting rid of an infestation. While the pests leave noticeable trails of waste along their favorite routes between nests and food sources, this doesn’t mean removal will be easy. House mouse droppings cause several health problems, so finding a nest is only the beginning.


Sounds of scratching, rustling, and squeaking coming from walls, attics, crawlspaces, sheds, or garages may also indicate a large incursion of mice.

Prevention Tips

Proper sanitation may help reduce the likelihood of a house mouse invasion. While no amount of sanitation will keep mice away for long if food still remains available, preventative actions like properly storing groceries and pantry items, eliminating attractive nesting sites, and sealing off points of entry to the home can help. Applying steel wool mixed with caulk around openings for pipes and wires may also help to keep mice away, as does the use of metal and concrete where necessary.

Tips for Removal from Home

Store-bought traps and baits can eliminate small populations of house mice. For larger infestations, a trained pest control specialist may need to come remove the problem. Specialists are trained in the proper utilization of chemicals and traps and know how to remove and dispose of dead or captured rodents safely and appropriately. Additionally, pest control professionals can build an integrated pest management plan designed to keep house mice out.

Scientific Classification: Mus domesticus, Mus musculus

Class Order Family
Mammalia Rodentia Muridae