How bumblebees avoid accidents while flying

Even as makers of next generation drones take inspiration from flying animals to make the robots more efficient in navigating the cluttered urban environment, researchers have unraveled how bumblebees avoid collision.

"Bumblebees use what is known as an optic flow to help them avoid crashing into surrounding objects," said Christine Scholtyssek Lund University in Sweden.

The optic flow can be described as the sensation that surrounding objects move as the bumblebee flies past.

To the bumblebee, reality is reversed - it is as though the bee remains still while the objects speed past.

Humans can have a similar experience when travelling by train, for example, when the surroundings race past the window.

The closer the bee comes to an object, the faster the object appears to move, that is the optic flow in the bee's field of vision grows stronger.

If the optic flow suddenly becomes stronger in the right eye than the left, the bumblebee will turn left to reduce the risk of a collision.

"The bumblebee has to constantly balance the optic flow between its two eyes," said Scholtyssek.

The researchers used specially constructed tunnels containing water and air to compare the optic flow of swimming and flying creatures respectively.

The results showed that zebra fish also use optic flow, but it did not react in the way the researchers had expected.

"Surprisingly, the fish steered towards a stronger optic flow rather than away from it like the bees," Scholtyssek noted.