Wild Mice FAQs
The most common type of mouse found in urban environments is the house mouse (Mus musculus), which originated in southern Asia. They prefer to live in buildings close to human food supplies, but in an appropriate climate, can survive in the wild where they will dig burrows with several underground chambers. House mice vary in colour from light brown to dark grey with a lighter colour on their bellies. They have proportionately large ears, small eyes and small feet and weigh less than 28 grams.
Deer mice (Peromysus maniculatus) are native to North America and are very similar to the house mouse. The distinguishing feature is that the deer mouse’s tail is brown or grey on the top and white underneath, in contrast to the house mouse whose tail is the same grey-brown as its body.
Deer mice generally nest in underground burrows but may sometimes invade buildings near fields and woodlands.
Mice are omnivores and will eat a variety of things. They seem to prefer cereals, seeds and nuts but also like foods high in fat and protein such as butter, bacon, meat and sweets. A mouse requires about three grams of food each day and can live without access to fresh water. Because they do not hibernate, they will store large quantities of food in different places, to rely on in harsh weather. As with all rodents, mice must gnaw to keep their front teeth worn down and can chew through wood, aluminum, soft mortar and asphalt.
There is a definite social ranking among mice that is linked to protection of individual territories that are scent- marked with urine. Subordinate mice tend to feed and be sexually active when the dominant males are inactive, generally during the day. Unrelated males are highly aggressive toward one another. Males tend to have larger territories than females and each mouse will travel its entire territory daily to investigate any changes that may have occurred.
Mice are nocturnal and house mice breed throughout the year. A mouse will have eight to ten litters of 3-16 young annually, each with a lifespan of about one year. Their reproductive life begins at one and a half to two months of age. They are excellent jumpers and climbers, being able to jump from a height of 2.4 m without injury, or jump up to 30 cm off the ground. They can squeeze through openings slightly larger than 7 mm in diameter and are capable swimmers if they need to be.
Most species of mice have adapted very successfully to living in close proximity to humans. They often nest and live in buildings, and can squeeze through very small spaces. Compared to other types of urban wildlife, mice pose a particular challenge for residents due to their small size, their year-round prolific breeding capacity, and their ability to thrive in an indoor environment.
The presence of mice in our homes often causes significant concern and fear among residents. Mice can do considerable damage by gnawing their way through wood, paper, clothing, and other materials to get into containers, cupboards, drawers and other areas. They may also carry diseases or parasites that could be passed on to you or your pets. Food that has been contaminated by mice should always be avoided.
Precautions must be taken against disease by properly cleaning areas where mice have been. But we must remember that these little creatures, like all wildlife, are opportunists seeking food and shelter. We must make sure we don’t provide the opportunity they are seeking.
When human-wildlife conflicts occur, a little understanding of the animals’ characteristics and needs will help us take a humane and patient approach leading to a peaceful coexistence. Humane treatment of an animal involves compassion and respect, precludes cruelty and avoids pain, suffering or injury.
The first line of defence, as with all wildlife conflicts, is to try to prevent access as much as possible and remove food sources. Since house mice in particular generally live indoors, it is very difficult to get them to leave voluntarily. But removing their reason for being there (mainly food) will go a long way towards reducing their numbers.
Do you have a problem with mice? Visit the Ottawa-Carleton Widlife Centre's website!
For more information on mice, contact the Ottawa Humane Society at 613-725-3166 ext. 262, or send us an email.
Information from the Canadian Federation of Humane Societies.
