The Norway lemming has many adaptations that allow it to thrive in its harsh environment.  Some behavioral adaptations that the Norway lemming have developed are migrating and burrowing.  In the winter, Norway lemmings migrate to dryer areas.  Norway lemmings do not hibernate, but burrow underground to escape the cold.    Because they do not hibernate, Norway lemmings, and all non-hibernating rodents, undergo varying amounts of heat production.  The amount of heat production is controlled by the thermoregulatory system.  It is a system of glands that release melatonin to control heat production. Physically, Norway lemmings have teeth highly adapted for gnawing on plant matter.