A team of researchers has found that bumblebees can learn to pull a string in order to access a food reward, a behavior that’s only been seen previously in vertebrates. Interestingly, the bees were capable of learning this behavior by watching a demonstrator bee that had already solved the puzzle. The findings may change our current understanding of the cognitive abilities of social insects. The details are in a paper that was just published in the journal PLOS Biology.
Social learning has been documented in many vertebrate animals but is poorly understood in social insects, such as bees. One simple test used with other animals is a string puzzle, in which the animal has to pull on a string for a reward. Researchers from Queen Mary University designed a similar test for bees, using fake flowers that contained sugar water.
The team trained bumblebees to pull on a string in order to access the sugar water treat. Interestingly, some of the bees learned this skill without any training, much to the surprise of the researchers. The bees that acquired the string-pulling skill were labeled as “innovators”. The researchers then placed 25 untrained bees in an enclosure where they could watch innovator bees solve the puzzle. About 60% of these “naïve” bees learned to pull the string just by watching the trained innovator bees.
The researchers then tested whether or not the string-pulling skill could be transmitted culturally throughout a colony. The team introduced a single innovator bee to three separate colonies of untrained bees. The skill spread quickly and half of the untrained bees gained the ability by learning from the original innovator bee. Even after the original innovator bee died, the skill continued to be passed down to future generations. This was the first recorded case of cultural transmission of a non-natural skill in social insects.
The team’s findings provide new insights into bee learning and cognition. The researchers showed that even small-brained insects, such as bumblebees, can solve complex non-natural tasks. Furthermore, these skills can be passed on culturally and a colony can learn by watching the original innovators.
Sylvain Alem et al. Associative Mechanisms Allow for Social Learning and Cultural Transmission of String Pulling in an Insect. PLOS Biology (2016).