Bumblebees Detect a Flower’s Electric Buzz With Their Fuzz

The vibrant colors of a field of flowers can certainly be called electric, but this description isn't just poetic—it's also literal. A flower’s delicate form generates a weak electric field. Now, a new study shows how bumblebees can sense that electric buzz, reports Nell Greenfieldboyce for NPR. The secret is in their fuzz.

"There is, all the time, a background electric field in the atmosphere," the lead scientist of the research team, Gregory Sutton, tells Greenfieldboyce. "Any plant that's connected to the ground will generate its own electric field just by interactions with the atmosphere."

In 2013, Sutton and his colleagues first showed that bees could sense these minute charges by using electrically charged fake flowers. But until now, scientists didn’t know how bees could do it, writes Chelsea Harvey for Mashable.

This latest research, published this week in the Proceedings of the National Academy of Sciences, points to bees' tiny hairs. Using a sensitive laser, the researchers measured the minute motion of a bee’s hairs and antennae when exposed to a weak electric field like those of the flowers. The results suggest that the hairs are much more sensitive than the antennae to electric fields. Though the electric field caused both to move, the hairs—lighter and thinner than antennae—were both faster to respond and showed greater movement.

The researchers also detected nerve cell activity in anesthetized bees by inserting itty bitty electrode wires at the base of the hairs and antennae. When the hairs start waving in the electric field, the neurons at the base of the hairs increased firing. This was not true for the antennae, reports Harvey.

The phenomenon is similar to what happens to human hair when you rub a balloon on someone’s head—the hair stands out towards the balloon, Sutton describes in a press release. But for the bumblebees, the feeling of these bending hairs could perhaps help them tell the difference between flower types, Sutton tells NPR. 

Bees are not the only creatures that scientists have found are sensitive to these slight electric fields. Creatures like sharks and rays have electrosensory organs that contain a conductive jelly that can detect electrical changes in the water, reports Mo Costandi for The Guardian.

But since air does not conduct electricity, the ability was thought to largely be limited to denizens of the watery or wet environments, where the water could help convey the buzz.

"I'm very excited by this because these little mechanically-sensitive hairs are common all over the insect world," he tells Greenfieldboyce. "I think this might be something we see in more insects than just bumblebees."

Even so, the why of detecting these electric fields remain less clear, Robert Gegear, biologist at Worcester Polytechnic Institute, tells NPR. The superpower may not necessarily be related to collecting pollen, he notes. Bees could be even be detecting electric fields for navigation or communication.

As bee populations plummet, scientists are swarming to learn more about these insects. From robo-bees even to vibrators, researchers are combing through the techniques that bees use to get the job done. Bees are amazing little creatures, electric field sensing fuzz adds to their buzz.

Maya Wei-Haas | | READ MORE

Maya Wei-Haas is a freelance science writer who specializes in geology of Earth and beyond. Her work has been featured in National Geographic, News from Science, and AGU’s EOS.