Posted 3:17 p.m. Wednesday, Aug. 5, 2020

Thermal images of bees.

Back to the basics on bees: Study distinguishes sleep from other activities inside the honeycomb

We’ve long known the importance of honey bees beyond their sweet honey. These insects are largely responsible for the livelihood of our planet as they busily pollinate flowering plants and crops — many that make their way to our plate. So, good bee health should be a priority for everyone. 

Like humans, it appears sleep is important to the health of bees. In fact, previous studies indicate sleep may improve communication and even memory. But to truly study bee sleep, scientists need to know when and where it happens and what it looks like — even if that requires peering deep into the confines of the honeycomb. 

Barrett Klein, associate professor of biology at the University of Wisconsin-La Crosse, recently published a study in PeerJ that distinguished bee sleep from another major activity happening inside the honeycomb: heating developing brood. He used an infrared-sensitive video camera and a thermal camera to analyze the bees and determine sleep based on breathing and the presence or absence of major body movements. 

Sleep appeared frequently enough, constituting 16.9% of observations, to suggest that it is an important behavior experienced within a honeycomb, supporting previous examinations of sleep inside comb cells, and lending credibility to future ventures, says Klein. 

Studying bee sleep takes some innovation as Western honey bees spend much of their time inside honeycomb cells with only the tips of their abdomens visible through the walls of an observation hive, or on frames pulled from a typical beehive. Klein’s method shows how future insect observations can rely on similarly less invasive manipulations to reveal the dynamics and functions related to sleep in nature. 

Barrett Klein, UWL associate professor of biology, studies insect behavior, sleep biology and the ways insects have affected humans throughout history.