"Say it with flowers," went the old advertising slogan, but who knew flowers were this talkative? It turns out flowers give off electrical signals that bees can pick up on, telling potential pollinators whether a flower has plenty of nectar or has recently been tapped, reports NPR. According to scientists at the University of Bristol, flowers have slight negative charges, while bees have positive charges in flight; the presence of a bee changes the flower's charge, a change that lasts for about 100 seconds after the bee leaves.
"This is a magnificent interaction where you have an animal and a plant, and they both want this to go as well as possible," says one of the researchers. Flowers also use color and scent to attract bees, of course, but those characteristics are much harder to change than a slight electric field, so are less useful for informing pollinators whether a flower is full of nectar or running empty. It's not known yet how a bumblebee detects the flower's charge, but scientists suspect the electrostatic charge affects the bee's body hairs. Click to read the University of Bristol's original press release about the discovery.