A new study published in the Journal of the Royal Society Interface saw British and Spanish researchers take a deep dive into the combs of Tetragonula, a stingless bee from Southeast Asia and Australia, to understand how, without some sort of comb blueprint, these animals could so consistently create these complex structures. They found that the bizarre spiral shape of their nests, which have long been a source of confusion for scientists, are crafted in a pattern that is similar at a molecular level to crystal development. Using mathematical modeling, they were able to simulate the comb’s construction and concluded that the bees only needed to glean information from their local environment to create the overall structure in a way that mirrors the behavior of molecules in a crystal.
Tetragonula bees build impressive combs made up of terraces stacked on top of one another, which spiral outwards in a fashion that appears far too refined to have been improvised by insects. The edge of each terrace is built upon by worker bees who craft a new cell, which is then stuffed with an egg and sealed shut before the bee goes on to repeat the process. The end result is a spectacular comb that exhibits spirals, double spirals, and bullseye-shape patterns within its architecture.
The researchers noticed the comb’s shape was similar to the natural growth of crystals, which are also made up of three-dimensional patterns with spirals and target patterns. While it’s known that bees are highly social animals and capable of communicating messages, it seemed a stretch to imagine that the enormous creations were the result of bees working to a blueprint. They hypothesized that chemical signals could be another way in which the worker bees were being directed, but wanted to test if there were limitations to the structure’s survival, which meant the bees would naturally come to the design without instruction from higher up the construction line.
Using a model to investigate the comb’s development, they were able to identify limitations to the comb’s structural stability, which meant the worker bees needed to connect the new cells to at least two other existing cells, and where this wasn’t possible they moved along the comb. This way of mapping connections based on local information mirrors the way in which molecules behave in a crystal. The researchers say this comparison demonstrates how similar patterns can emerge in completely separate systems as complex structures are made up of links that only function if they adhere to simple rules of development.
This structural limitation of the comb’s development meant that the bees were able to come to the overall design without the motivation of working to an end goal. The decision of the bees to attach a new cell wasn’t dictated by the desire to create a vast, spiraling structure but simply knowing where the best place was for that single cell. That said, I wonder if they ever go for a spin around the comb to gaze upon their architectural mastery.