The frost that strands a cluster

A colony can starve in midwinter with honey still in the hive. The cluster eats the stores around it and moves slowly across the comb. A mild day lets it shift; a hard frost the next morning pulls it tight wherever it is. If that is away from its stores, the bees cannot cross the cold comb to reach them, and colonies have been found dead with capped honey a hand's width away.

Small colonies are likelier to be caught. The remedy is sugar where the cluster already is: a slab of dry sugar laid over the frames, above the bees. It is the one feed that belongs in deep winter, when they cannot take syrup.