Most of the U.S. is in the midst of winter weather right now, but the hot days of summer are right around the corner. Humans don’t have a monopoly on trying to figure out how to stay cool during the hot summer months. Harvard scientists have been researching how exactly bees keep their hives cool in the hot days of summer.
Scientists have known that when it gets too hot in a nest for bees, a group will go to the entrance to the hive and flap their wings. That draws out the hot air and brings cool air into the hive. What the team wanted to know was how exactly the bees organized to perform the cooling action.
The answer sounds rather complicated. Jacob Peters, the first author of the paper, says that there is no sophisticated recruitment or communication scheme between the bees to organize a cooling party. Instead, according to Peters, the fanning response of each bee to temperature variations and the physics of fluid flow leads the bees to a collective spatial organization, which happens to lead to an efficient cooling solution.
The team started to experiment with bees in artificial hives in a lab setting in the summer of 2017. The team measured temperature, air flow in and out of the nest, and the population density of bees fanning near the nest entrance. The scientists discovered that rather than spreading out across the entire nest entrance, the bees clustered in the hottest areas and kept the areas with the highest air outflow separate from the cooler areas with highest air inflow.
Researchers also found that bees had different temperature thresholds above which they would start to fan allowing the hive to be better at responding to temperature variations. All the behaviors were found to be linked to environmental physics of the nest. The findings in the study could one day lead to bioinspired HVAC systems adapted using what they discovered to respond to cooling demands better than current systems.