Biology and Habits

House mice produce an average of 8 litters per year with an average of 6 young. Breeding occurs after 35 days and the gestation period lasts for approximately 19 days. The average lifespan of a wild mouse is typically less than a year, but they can live longer in captivity.  Mice are most active at night, but can be seen during the day, especially when populations are high. They are excellent climbers and will travel between 10 – 30 feet from their nest, depending on population density. House mice will establish territories and males will aggressivly defend them against other mice. House mice do not carry hantavirus, however, they can transmit bacteria that causes food-borne illnesses.

While mice may infest homes during the warmer months, they are most often seen indoors in the fall and winter. As their natural food source becomes scarce and the temperature drops, they may move inside to establish a nest. Some house mice live their entire lives indoors. Well adapted to any environment, mice can nest in just about any suitable location; ceiling and wall voids, behind appliances, in wood piles, sheds, garages, attics, etc. As omnivores, they have a wide variety of food they may feed on, including seeds, grains, insects, and even human and pet food. 

Control

House mice are effectively controlled through a variety of methods. With existing indoor infestations, snap traps or bait are effective means of control, however it is important to ensure that bait is placed in tamper proof containers to prevent access by non target organisms, people, and pets. Baits and traps should be placed in areas where mouse droppings and feeding occurs. If there is no activity after 48 hours, move baits and traps to new areas. Exterior control can also be achieved with baits and traps around the perimeter of the structure. 

Where possible, exclusion is effective in preventing entry into the structure. Sealing up openings with hardware cloth, steel wool, spray foam, or other means will effectively block access. Look for areas where pipes, conduits, or wires enter the home, under siding, around worn out door or window frames, or areas where additions to a home or building meet the original construction. Unfortunately, there are many situations where exclusion is not realistic, either due to cost of repair or location of the opening. For example, many mice gain access to homes from inaccessible entry points located under decks.