Most mammals do not hibernate. They remain active throughout the winter and have various strategies to conserve heat. A thick coat of winter fur increases insulation by up to 20 per cent. Shrews and small rodents like mice and voles stay under the snow, finding food in an environment of constant temperature and humidity. Temperatures below the snow can be up to 25°C warmer than on the exposed surface. Winter nests constructed of dried plants and fur provide additional insulation. Many small animals live communally in winter, huddling together in their winter nest or den to reduce heat loss.
Snowshoe Hares and Lynx move easily on top of snow. Dense fur on the soles of their feet acts as snowshoes. Caribou don't sink in deep snow — large semicircular hooves and prominent dew claws located behind the main hooves prevent this.
Snowshoe Hares and Ermines depend on concealment to escape predators. In winter, they acquire a white coat that provides effective camouflage against a snowy background.