Bees need fresh air. Foul air will cause excitement, causing an overheated condition; and the bees will scatter and die. Any excitement among bees in winter is fatal. Cellars on high ground, covered with straw over timbers, are best for wintering bees. If the bee cluster divides or splits up during the winter, the smaller clusters will perish from cold. The present style of Hoffman frames divides the bee cluster into eleven divisions separated from each other by a sheet of wax comb, with no direct communication between different divisions except over, below or around the frames. If the bee cluster contracts during the winter on account of cold the divisions of the outside frames are sometimes left behind and die. Some bee keepers perforate their frames to keep an easy passage for bees from one compartment to another. If kept warm, even weak colonies may pass over or around the frames without much difficulty. When cold, only the strongest will be able to accomplish this difficult task. Wintering bees in division hives or in two story hives, which give them a horizontal bee space through the middle between the two divisions, is highly recommended for successful wintering. [Illustration: Francis Jager, Professor of Apiculture, University Farm, St. Paul.] In long-continued severe cold the bee clusters will contract into a very small, compact mass. The tendency of this cluster is to move upward where the air is warmer. If enough honey is stored above them they will keep in contact with it. If the honey is stored at the side, the bees sometimes lose their contact with it and die of starvation and cold. This is another argument in favor of wintering in two story hives. Often they will move towards one corner and die there, leaving the other corners filled with honey. If you must winter in one story hives give bees plenty of honey in the fall and place the cluster at one side of the hive so that they move necessarily toward the honey supply. Bees should be kept in a cellar at a temperature of about 45 degrees. The difference in the temperature between the outside and the inside of the hive will be between 10 and 15 degrees. Very strong colonies, no matter where kept, will keep themselves warm and will survive any degree of cold, but there is no doubt that their vitality and ability to stand wintering will suffer a great deal thereby, causing dwindling in the spring. Cellar wintering is at present general in Minnesota. The bee cellar should be warm, dry, dark and ventilated. The bees should not be disturbed during their winter sleep by pounding, jarring, shaking and feeding. Mice also may cause the bees to get excited and perish. A four to one inch wire screen in front of the entrance will prevent mice from getting inside.