*clears throat*, if you'll open your book of solved aviation mysteries to page 74:
"And this was just for hovering," Altshuler said of the bees. "They also have to transfer pollen and nectar and carry large loads, sometimes as much as their body mass, for the rest of the colony."
In order to understand how bees carry such heavy cargo, the researchers forced the bees to fly in a small chamber filled with a mixture of oxygen and helium that is less dense than regular air. This required the bees to work harder to stay aloft and gave the scientists a chance to observe their compensation mechanisms for the additional toil.
The bees made up for the extra work by stretching out their wing stroke amplitude but did not adjust wingbeat frequency.
"They work like racing cars," Altshuler said. "Racing cars can reach higher revolutions per minute but enable the driver to go faster in higher gear. But like honeybees, they are inefficient."
The work, supervised by Caltech's Michael Dickinson, was reported last month in the Proceedings of the National Academy of Sciences.