The white-footed mouse or deer mouse is a native species with white feet, white or light-coloured undersides, and brownish upper surfaces. The tail is distinctly bi-coloured; the upper portions brown or gray, the underside white, with a well-defined line where the two colours meet.
White-footed mice are about the same size as, or slightly larger than house mice and, at a distance, may be confused with house mice. The bi-coloured tail differentiates one from the other. In comparison to house mice, white-footed mice have larger eyes and ears. They are considered by most people to be more “attractive” than house mice, and they do not have the characteristic mousy or musky odour of house mice.
The white-footed mouse measures 50-90 mm (2 to 3 1/2 in.) in length with an additional 50 to 88 mm (2-2 1/2 in.) tail and weighs up to 90 g (3 oz).
Deer mice breed only in summer. Females of northern populations never have more than 2 litters (of about 5 young). In southern Canada, females produce more, smaller litters; some may become sexually mature in the season of their birth. A few animals are known to have survived 2 winters. Deer mice may destroy stored food and carry a virus (hantavirus) that in 15-50% of cases is deadly to humans. The virus is transmitted from feces and urine of deer mice deposited on food or inhaled as dust. They provide food for carnivorous BIRDS and MAMMALS.