Insects are very complex and complicated creatures, even more so than scientists thought they were.
How do bees drink nectar? Scientists have thought for nearly a century that the only way they drink is to lap up the nectar. Not in the way a cat or dog laps liquid. High speed video now shows how they dip their hairy tongues in and out of nectar, a syrupy liquid, and draw it up into their mouths.
Now scientists are aware that bees can also suck nectar. This is a more efficient way to consume nectar when it is lower in sugar content, which makes the nectar thinner. Bees’ tongues are very sensitive to the viscosity of nectar.
This 4:20 minute video by Life Zoomed In is a magnificent close-up of a honeybee's face, eyes and tongue:
Bees are very versatile nectar drinkers, able to switch back and forth between lapping it up and sucking it up. They do so depending on the degree of viscosity of the nectar, in order to get the best reward based on the energy expended. High-speed video clearly demonstrated this in a lab, where bees drank a nectar substitute.
Senior researcher on the experiment, Jianing Wu, is a biophysics and engineering specialist at Sun Yat-sen University in Guangzhou, China. He and his team found that while honeybees excel at feeding on highly concentrated nectar, they also switch their feeding strategy with ease from lapping to suction when they need to adapt. He and his colleagues recently reported their findings at Research Gate in Biology Letters. You can study their images and findings here.
Dr. Wu explained that when the honeybee tongue laps syrupy nectars, 10,000 or so bristles covering their tongue go erect all at once at a certain angle so the nectar can be trapped. Then the bee pulls its tongue back into its proboscis, part of its mouth, and a pumping mechanism in the bee’s head sucks the nectar off the tongue. When the nectar is thinner, the bees let their tongues remain in the nectar and suck it up into their mouths using the same pumping mechanism.
This 0:30-second video by Dogspeed Films shows amazing footage of a bee grooming her tongue:
David Hu is a professor at Georgia Institute of Technology. He supervised earlier research by Dr. Wu but was not involved in this experiment. He said researchers thought insect tongues worked in one way, but Dr. Wu has shown that honeybee tongues can effectively drink many types of nectar by using their tongues in various ways.
Dr. Hu finds this makes perfect sense since honeybees are generalists that forage on many flower types. They are not limited to just one type of flower like some other bees, so they are able to adapt to their food source conditions.
Alejandro Rico-Guevara also worked on the project. He runs the Behavioral Ecophysics Lab at the University of Washington, Seattle, where he studies birds and how they feed on nectar. He finds it important that bees can feed from flowers with more watery nectar as well as the thicker, more syrup-like nectars which they prefer. This behavioral adaptability has many implications for pollination, for our food availability and for the role bees play in natural ecosystems.
It is exciting that we keep learning more about bees as scientists solve some of their mysteries with new technology.