We often think of winter in northern regions as a time of dormancy or hibernation where animal life is quiet or non-existent. But, the subnivean zone is full of life! If we break it down, sub means under and nivean refers to snow. So, there is LIFE under the snow. What lives there, and how do they survive? Snow actually acts as an insulator, trapping air between the flakes and the heat that emanates from the ground. Lots of small creatures find refuge and a nice little habitat in this coziness. Mice, voles, and shrews are the most common inhabitants, creating little tunnels under the snow to get to food and shelter. They will typically make entrance and exit holes in the snow leading to these tunnels. The holes serve as tunnel access points, but they also allow the animals to have fresh air.