Scientists say bumblebees can sense flowers’ electric fields through the bees’ fuzzy hairs. Jens Meyer/AP

Thanks to National Public Radio (USA) for this small scale science lesson:

Bumblebees’ Little Hairs Can Sense Flowers’ Electric Fields

The fields bend the hairs and that generates a nerve signal, scientists say.

Flowers generate weak electric fields, and a new study shows that bumblebees can actually sense those electric fields using the tiny hairs on their fuzzy little bodies.

“The bumblebees can feel that hair bend and use that feeling to tell the difference between flowers,” says Gregory Sutton, a Royal Society University Research Fellow at the University of Bristol in the United Kingdom.

People used to think that perceiving natural electric fields was something that animals only did in water. Sharks and eels can do it, for example. The platypus and spiny anteaters were the only land critters known have electroreceptive organs, but these have to be submerged in water in order to work.

Then, a few years ago, Sutton and his colleagues showed that bumblebees could sense electric fields in the air.

“There is, all the time, a background electric field in the atmosphere,” says Sutton, “Any plant that’s connected to the ground will generate its own electric field just by interactions with the atmosphere.”

He wondered if bumblebees could sense those electric fields and use them in some way. So his team tested that idea with the help of a bunch of almost identical artificial flowers.

The scientists took half of the flowers and put 30 volts on them, then filled them with sugar water. The other flowers were filled with a bitter liquid. “And the bees will eventually learn to go to the ones that are charged to 30 volts,” says Sutton.

When they turned off the voltage, the bees lost the ability to differentiate between the flowers and began to forage randomly, showing that the bees really were relying on those electric fields.

But how were the bumblebees able to sense them? That’s what the researchers tacked in their latest study, described in the Proceedings of the National Academy of Sciences.

“We used a laser beam that could measure small motions of an antenna or a hair, and that’s how we measured how much the air and the antenna moved in response to an electric field,” says Sutton.

They also stuck a very fine electrode wire into the nerve at the socket of the bottom of a hair to record the activity of nerve cells there.

“They’ve got these really fuzzy hairs all over their body, and when they approach something with an electric field, that electric field will bend the hairs on their body,” says Sutton. And that bending generates a nerve signal…

Read the whole article here.