An absolutely amazing study was recently published about bumblebees learning how to pull a string to get food. And not only that, bumblebees learned how to do it from other bumblebees. (Yay, bees!)
The set-up: Sugar water (food) was available in a blue plastic “flower.” Bumblebees learned to drink the sugar water from the flower, and then the flower was placed more and more underneath a Plexiglas “table.” There was a string attached to the flower so that the bees simply had to pull the string with their front legs or mandibles (mouthparts) to slide the flower out from under the table.
Here is an awesome picture of what this set-up looked like. I LOVE the picture because it is so clear and you can even see the label that was glued onto the bumblebee’s thorax! This bee must have been Yellow #5 or Yellow #15 (I can’t quite see if it’s one or the other).
Here is a diagram showing the steps the bumblebees needed to learn the task:
With training like this, most bumblebees learned how to pull the string to get at the flower. When you think about it, this is pretty amazing behaviour for bumblebees because they don’t need to do anything like string-pulling in nature to get at nectar in flowers.
And if that wasn’t cool enough, the researchers found that bumblebees never exposed to the string-pulling task learned how to pull the string to get the food by watching other bumblebees do it! Social learning! In bumblebees! (BOOM! Mind blown!).
During graduate school with my own bumblebee experiments, I sometimes wondered if bumblebees could learn from other bumblebees–what is called social learning. When bumblebees were drinking from my own artificial flowers I would often see bumblebees who had never been to the flowers before make a “bee-line” to the flowers and start to drink (or, if a bee was already there, crash into it, knock it out of the way, and then start to drink!). I wondered if the bumblebees could recognize other bumblebees and learn what the other bumblebees were doing.
These little critters sure are impressive. Just think: they have a brain the size of a sesame seed, but can learn a complex task like pulling a string…even learn it from other bumblebees. Quite the cognitive toolkit that is packed into a brain that’s so much smaller than ours! Gives me a whole new appreciation for the animal kingdom and nature in general.
Here is a great video where you can see the experiments in action.
Alem, S., Perry, C. J., Zhu, X., Loukola, O. J., Ingraham, T., Søvik, E., & Chittka, L. (2016). Associative mechanisms allow for social learning and cultural transmission of string pulling in an insect. PLoS Biology, 14(10): e1002564. doi: 10.1371/journal.pbio.1002564.