Winter cluster

In beekeeping, a winter cluster is a well-defined cluster of honey bees that forms inside a beehive when the air temperature dips below 50 to 57 °F (10 to 14 °C). Honey bees are one of but a few kinds of insects that survive the winter as a colony. As the outside air temperature decreases the winter cluster becomes tighter and more compact. The bees cling tightly together on the combs in the hive. The temperature within the winter cluster remains remarkably warm regardless of the outside air temperature. Larger clusters (basketball size) have a better chance for survival than smaller clusters (softball size). The winter cluster within the hive must move throughout the winter to reach the available honey stored in the combs.

Some die-off is expected during the winter. In extended cold weather periods, the incidence of Nosema disease increases and the cluster may weaken as many bees begin dying off.

Brood nest

In subtropical climates, bees may not form a winter cluster at all. Worker bees forage and queens lay eggs almost year-round.