New York, Feb 10 : Honey bees live in large, congested cavities, often in tree hollows with narrow openings.
But thanks to their ventilation strategy they know how to stay cool on hot summer days, says a study by Harvard researchers.
When it gets hot inside the hive, a group of bees crawl to the entrance and use their wings as fans to draw hot air out and allow cooler air to move in, said the study published in the Journal of the Royal Society Interface.
The researchers found that bees use environmental signals to collectively cluster and continuously ventilate the hive.
"We have demonstrated that bees don't need a sophisticated recruitment or communications scheme to keep their nests cool," said first author of the paper Jacob Peters from Harvard University.
"Instead the fanning response of individual bees to temperature variations, and the physics of fluid flow leads to their collective spatial organisation, which happens to lead to an efficient cooling solution," Peters added.
For the study, the researchers monitored a group of man-made beehives in Harvard University's Concord Field Station.
The research team measured temperature, air flow into and out of the nest, and the position and density of bees fanning at the nest entrance.
"Over millennia, social insects such as bees have evolved to harness and exploit flows and forces and collectively solve physiological problems such as mechanical stabilisation, thermoregulation and ventilation on scales much larger than the individual," said senior author of the study L.
Mahadevan, Professor at Harvard.
"A combination of measurements and computational models quantify and explain how fanning bees create an emergent large-scale flow pattern to ventilate their nests," Mahadevan added.