Peering inside honeybee swarms: adaptive responses to temperature changes

Honeybee swarms, made up of a queen bee and thousands of workers, hang suspended from structures for periods ranging from hours up to several days while they search for a new hive. The dense aggregation dynamically adjusts its morphology when subject to temperature changes, contracting in response to cooling and expanding when heated, likely for thermoregulation. While changes in the external morphology of swarms subject to heating and cooling are well documented, the swarm's internal structure, where the majority of bees reside, remains elusive. Using x-ray computed tomography, we characterize the internal structure of honeybee swarms at varying ambient temperatures. We show how the swarms maintain both mechanical stability and thermoregulation by dynamically remodeling their internal structures in response to temperature changes of the surrounding environment.