Winter Cluster
Verhalten der Bienen
When outside temperatures drop to about 8 to 10 degrees, the bees pack tightly together and form a ball.
When outside temperatures drop to about 8 to 10 degrees, the bees pack tightly together and form a ball. In the outer shell they sit dense like a fur coat, while inside they generate warmth by shivering their flight muscles. In the broodless core it stays at around 20 to 25 degrees. The cluster slowly moves upward along the food stores.
In doing so, the bees do not heat the hive but only themselves. The empty space around them stays cold and does not bother them. What harms them is draft, damp, and jarring.
A long frost period becomes dangerous: if the cluster is stuck in place and the food directly above it is used up, the colony starves despite full combs at the edges. So in autumn make sure the food is positioned correctly, hang full food combs right where the bees are clustered, and in winter only check from outside.