Bumblebees learn to solve a puzzle by watching more experienced bees, and this behavioral preference then spreads throughout the colony, according to a study published March 7 in the open access journal PLOS Biology by Alice Dorothy Bridges and colleagues at the Queen Mary. University of London, UK.

Social animals such as primates are adept at learning by watching others, and previous work has shown that individual bees can learn tasks in this way, but it remained unclear whether this new behavior would then spread throughout the colony. To investigate, researchers tested six colonies of bumblebees (Bombus terrestris) using a puzzle box that could be opened by twisting a lid to access a sugar solution. The bees could rotate the lid clockwise or counterclockwise by pressing one of two differently colored tabs.

Bees feed from a puzzle box that opens by pressing the blue tab
Bees feeding from a puzzle box opened by pressing the blue tab Image 2 Credit: Alice Bridges (CC-BY 4.0)

The researchers trained bees to use one of these two solutions and then released these “demonstrator” bees into a foraging arena next to untrained bees and filmed them over a period of six to 12 days. Foraging bees with a demonstrator opened more puzzle boxes than control bees, using the same puzzle solution the demonstrator learned 98% of the time, suggesting that they learned the behavior socially rather than stumble upon a solution on their own. In experiments where multiple demonstrators each learned a different solution to the puzzle, untrained bees initially learned to use both methods, but over time they randomly developed a preference for one solution or the other, which then came to dominate in that colony.

The study is the first to document the spread of different behavioral approaches to solve the same problem in bees. The results provide strong evidence that social learning is important for the transmission of novel behaviors by bumblebee colonies, as previously shown in primates and birds, the authors said.

A bee opens a puzzle box by pushing the red tab to rotate the lid of the box clockwise.
Video credit: Bridges AD et al., 2023, PLOS Biology

Bridges adds, “These results in bumblebees, which are small-brained invertebrates, echo results previously found with similar experiments in primates and birds — which were used to demonstrate those species’ ability for culture.”

Magazine reference

  1. Bruggen AD, MaBouDi H, Procenko O, Lockwood C, Mohammed Y, Kowalewska A, et al. (2023) Bumblebees acquire alternative puzzle box solutions through social learning. PLoS Biol 21(3): e3002019. DOI: 10.1371/journal.pbio.3002019