Winterizing the Hive: Moisture, Mouse Guards, Candy Boards, and the Mentor Call

Winter is the season when most first-year beekeepers lose a colony. The bees survive cold weather easily by clustering around the queen and shivering their flight muscles to generate heat. What kills a winter cluster is not the cold itself. The colony dies from moisture, from starvation, or from a mouse invasion. Each of the three killers has a simple prevention step that a senior can complete in a single Saturday afternoon in October. The Honey Bee Health Coalition winter checklist, the Penn State Extension winter guide, and the American Beekeeping Federation senior winter guide all agree on the four-part plan. Done correctly, the plan brings 80 to 90 percent of healthy first-year colonies through the winter even in cold climates.

The first killer is moisture. Bees produce water vapor inside the cluster from respiration and from the metabolism of honey. The vapor rises to the cold inner cover, condenses into water droplets, and rains back down on the cluster. Cold water on bees is the fastest way to kill a colony. The fix is a top-side ventilation slot or a moisture quilt above the inner cover. The simplest method is to prop the inner cover open with two matchsticks at the front and back. A more reliable method is to build a quilt box, which is a shallow super filled with wood shavings or burlap that absorbs moisture and dries it out by the next sunny day. A quilt box can be built from one cedar fence board and a square of burlap in about an hour. Plans are free from Honey Bee Suite at honeybeesuite.com.

The second killer is the mouse. Mice move into hives in October when the bees are clustered and slow. A mouse builds a nest in the lower brood box, urinates on the comb, and forces the bees to abandon the contaminated area. The fix is a metal mouse guard installed at the entrance no later than October 15 in most of the United States. A mouse guard is a strip of hardware cloth or perforated metal that reduces the entrance to a half-inch slot, too small for a mouse to squeeze through. Mouse guards cost 5 to 10 dollars from any bee supplier or can be cut from quarter-inch hardware cloth with tin snips.

The third killer is starvation. A healthy hive enters winter with 60 to 90 pounds of honey stored in the brood boxes. A weak hive enters winter with 30 to 45 pounds, which often runs out in February when the queen begins laying again and the cluster expands. The fix is a sugar candy board placed on top of the brood boxes in January. A candy board is a frame filled with hard sugar candy that the bees can eat through the long February gap before the spring nectar flow. Candy board recipes are available from the local beekeeping club, the Honey Bee Health Coalition, and Honey Bee Suite. The candy is poured into a wooden frame, allowed to harden for 24 hours, and placed above the cluster.

The fourth killer is keeper neglect. A senior who walks away in November and forgets to check the hive until April often finds a dead colony. The prevention step is a monthly winter check. On a warm afternoon in November, December, January, February, and March, a senior should walk to the hive, listen at the side with an ear pressed to the wood, and confirm the low hum of a living cluster. If no hum is heard, knock gently on the side and listen for a brief defensive buzz. A silent hive is a dead hive. A senior who hears nothing in February should call the mentor right away. Sources include the Honey Bee Health Coalition at honeybeehealthcoalition.org, the Penn State Extension winter guide at extension.psu.edu, and Honey Bee Suite at honeybeesuite.com.