What is "bearding" in honeybees?

Bearding is a behavior observed in honeybees where they cluster outside the entrance of the hive, particularly during hot weather. This behavior occurs as a natural response to rising temperatures inside the hive. By forming this cluster or "beard," the bees can ventilate the hive more effectively, expelling warm air and bringing in cooler air. This aids in regulating the hive's internal temperature, which is crucial for the health of the colony and the proper development of brood.

The other potential answers describe behaviors or situations that do not accurately define bearding. While bees do exhibit protective behaviors for the queen and adapt to temperature changes during winter, these are not directly related to the phenomenon of bearding. Hive overpopulation can lead to various behaviors, but bearding specifically refers to the clustering behavior outside the hive under warm conditions.