Rats do not hibernate. They are active all year long and store food reserves for bad weather, although their breeding does slow down in winter.
Since rats don't hibernate, they need to find food and shelter to get through the winter. Generally, rats that live in domestic areas find shelter in homes, outdoor buildings, cars, and inside walls or structures. They seek hidden areas and tear up material, such as paper, to line their nests.
Rats living in wilderness areas seek shelter in logs, woodpiles, old burrows, hollowed-out trees and caves. Rats can squeeze through openings as small as 0.6 inches in diameter and can jump almost 40 inches vertically.