Everything You Need to Know About House Mice

Posted: May 17, 2021


Finding a mouse in your home can be emotionally distressing, and for good reason. Despite their small size, house mice can cause considerable visible and hidden damage in one’s home. They can carry diseases like hantavirus, and they often carry fleas and mites which may feed on humans and their pets. Also, they may contaminate many areas with their saliva, urine, and feces.

House Mouse Identification

The house mouse (Mus musculus) is small, slender, lightweight, and furry. An adult’s tail is about as long as the combined length of its head and body, for a total length of 5¼ to 7¾ inches. Their fur is smooth and their coloring is darkish on their backs and light brown or white on their bellies, but their tails are semi-naked and uniformly dark. They have small eyes and large ears.

House mice are similar in appearance to deer mice, which are bicolored. Deer mice are pale grayish tan to deep reddish brown on their backs and white on their bellies with a distinct line where the two colors meet, and their tails are sharply bicolored.

Signs of A House Mouse Infestation

Mice can be identified by their appearance, but their presence can be apparent by far more than that. According to the National Pest Management Association, some signs of a house mouse infestation include:

  • Gnaw marks: House mice leave chisel-like markings on surfaces around holes that they use to gain entrance or find food
  • Droppings: House mouse droppings are ⅛ to ¼ inch long and rod-shaped, and have pointed ends
  • Tracks/footprints: House mice have four toes on their front feet and five toes on their back feet
  • Rub marks: House mice leave dirty, greasy streaks on vertical surfaces along walls as they move throughout a home
  • Runways: House mice frequently use the same paths, usually along walls and stacked materials
  • Damaged goods: Mice prefer seeds and cereals and may damage food containers to get them

Where Do House Mice Nest?

Mice like to nest in soft, warm places. They will build nests and raise young in wall or attic insulation, storage boxes or drawers that contain paper or clothing, in unused upholstered furniture or bedding, and in other similar places. They will harvest soft materials such as shredded paper, cloth and cotton to line their nest area, which will be located in that undisturbed area or void.

Why Are House Mice Dangerous?

House mice can be much more than just a nuisance. They can spread a number of diseases through their droppings, urine, and saliva, which can become airborne. The most threatening disease they carry is salmonella, which can contaminate food sources and cause food poisoning. Other diseases they carry include infectious jaundice/leptospirosis/Weil’s disease, which transmits via their urine, bubonic plague, and typhus. In addition, mice can spread airborne allergens that contribute to respiratory problems such as asthma. Finally, mice gnaw and chew on various objects because their incisor teeth continually grow and must be kept worn down. Unfortunately, they often gnaw on electrical wires, which can cause electrical shorts and occasionally even fires.

House Mouse Habits

House mice are opportunistic feeders and nibblers. They feed mainly at two times during the day, at dusk and just before dawn, with many mini-feeding times in between. House mice leave droppings and droplets of urine wherever they spend time or travel. They prefer dark and secluded nesting sites that contain abundant nesting materials, and they can squeeze through an opening of only 1/4″ to get where they want to go.

Rodent Control and Prevention

There are many things you can do on a day to day basis in your home to prevent or control a house mouse infestation:

  • Keep grass mowed to less than 3 inches in height. High grass provides a place for them to hide and move around, and seeds are mouse food.
  • Eliminate clutter. Mice love to turn cluttered areas into nesting areas.
  • Create a one-foot, vegetation-free gap between the structure’s wall and any plants. This will help discourage mice from trying to dig into the walls of your home.
  • Be careful with how you store and put out bird seed—mice love it just as much as birds do.
  • Seal off any entry points that house mice may be using, including cracks around doors and windows, holes in walls ¼ inch wide or larger, and utility line entrances. Use concrete, silicone-based caulk, cloth, or metal mesh/steel wool, depending on what works best for each scenario.

House Mouse Traps

If you want to trap house mice, snap traps are the most efficient types you can use. Using small rodent baits like peanut butter or pieces of fruit, bait the trigger and place it against a wall where it’s likely to run. Other useful traps include self-contained live traps, glue boards, and rodenticides, though continued use of rodenticides is inadvisable since it can prove dangerous to children and pets. Also, a dead mouse may end up in an inaccessible floor or wall voids, which can attract flies and other pests and create foul-smelling odors.

Professional Pest Control

You can certainly try to solve a mouse problem yourself, but many DIY mouse control solutions only work for a short time or don’t get rid of the whole problem. If you’re not successful or need help, it’s time to call in a pest control professional, who will perform a thorough inspection and help you create a plan to eliminate the mice in and around your home. Contact us today for a free inspection!