An Australian-led team says it has uncovered the secret to the agile flight of the bumblebee, which could influence the next generation of drone technology.
To understand how the bees navigate their environments, researchers created an obstacle course consisting of a tunnel separating their hive from their foraging area, blocked by a series of gates with different-sized holes.
A high-speed camera followed them whizzing through without a hitch, demonstrating a keen awareness of the layout of their surroundings and an accurate sense of their own body size and capacity for movement.
This is the first time that such evidence has been seen in flying invertebrates.
“Previous research had indicated that complex processes, such as the perception of self-size, were cognitively driven and present only in animals with large brains,” explains lead author Sridhar Ravi, from UNSW Canberra.
“However, our research indicates that small insects, with an even smaller brain, can comprehend their body size and use that information while flying in a complex environment.”
The project was a collaboration between UNSW Canberra, Bielefeld University and the Max Planck Institute in Germany, and Brown University and the University of California in the US. The findings are published in the journal PNAS.
Bumblebees were chosen as a model because of their body size varies greatly, even within a colony, and they have a proven ability to move through densely-cluttered environments to forage.
The researchers observed bees of all sizes using a process called “lateral peering”, in which they paused in front of an aperture and flew side-to-side to give themselves time to assess it, before choosing how to adjust their posture to fly through. The narrower the gap, the longer the bees took to scan it, with the largest bees taking the longest time.
In all 400 flights observed, the bees made it successfully through every gap, though their wings occasionally clipped the edges of smaller gaps.
In extreme cases, bees were even observed turning 90 degrees to fit through a gap smaller than their wingspan, like humans turning their shoulders sideways to fit through a narrow doorway.
“We were amazed to see that in some instances, the bumblebees reoriented themselves sideways to fly through gaps they were unable to attempt head-on,” says Ravi. “The dexterity of these insects has really got us thinking about what other secret bee behaviours we could unlock.”
This remarkable spatial- and self-awareness may be widespread in insects, and it may find applications in future technologies such as drones and autonomous vehicles, helping them to meet the challenges of navigating real-world environments.
“Insects are fantastic models for robots because they have exceedingly small brains and yet they’re able to perform overly complex tasks,” Ravi says.
“Over thousands of years nature has coded insects with some amazing attributes. Our challenge now is to see how we can take this and apply a similar coding to future robotic systems, enhancing their performance in the natural world.”