Here in the northern hemisphere when winter arrives and daylight shrinks, the bees form a cluster inside the hive; the bees maintain a cool resting temperature of about 70 Degrees F, and then the queen stops laying eggs.  The bee population is at its lowest before the Winter Solstice. As daylight hours increase, the bees increase the temperature of the hive to a brood rearing temperature of 95 Degrees F.  The increase in warmth spurs the queen to lay eggs.  She will build a small brood nest and gradually over the course of many weeks, the hive population  grows and by spring will explode and the hive emerges healthy and ready to gather pollen and nectar and begin another season.

(wintering bees facts was derived from Hive Tracks found at www.Hivetracks.com)