When I first moved to southern Ontario I visited the lab of Dr. Peter Kevan at the University of Guelph. He showed me video footage of bumblebees moving objects–paper discs and little balls–so they could get at nectar. It was amazing! I thought of all the cognitive and motor steps they needed to learn, in order to know to lift or push something out of the way to get to a goal.
I was happy to see that Peter has published this work in the journal Animal Cognition.
Unfortunately I don’t have the video footage of the bumblebees moving the discs and balls in Peter’s experiment. But basically the “flowers” were holes in a tray with a small tube of sugar water attached underneath each hole. The bumblebees could stick their tongues down the holes and suck up the nectar. After the bumblebees learned that they could get food from these holes, he covered them with a disc. At first, the bumblebees could move the disc in any direction off of the hole: left, right, or lift it up. Then the bumblebees could only lift it either left, right, or up. Then, for the last task, there was a ball placed over each hole, each ball having a different weight.
Most bumblebees were able to move whatever object was covering the nectar hole. The catch was that they had to have experienced an “easier” task before a “harder” task. So, they learned to move the disc in the right direction if they first could move it in any direction, and they learned to move the heavier balls if they first learned to move the lightest balls. Otherwise, if they experienced the hardest task first, they tended to fail and not get any food.
It makes sense that bumblebees are little food-obsessed problem-solving machines. Worker bumblebees only live for several weeks, and there can be well over 200 sister bumblebees to feed in the nest! Plus, not all flowers are handled the same way: to get at the nectar, sometimes bumblebees have to crawl inside, push petals out of the way, or perform some other kind of minor acrobatics.
Pretty impressive stuff for a creature with a brain the size of a grass seed!