For as long as mankind has pursued honey bees, he has been fascinated by the shape of comb cells. Since that first discovery, many types of intelligence have been ascribed to honey bees that might result in their extraordinary ability to build perfect hexagons. If you ever tried to draw a regular hexagon, one with equal sides and equal angles, you know how difficult it can be.
But the most plausible theory is that honey bees do not actually build hexagons. Instead, they build wax cylinders that conform to the shape of their bodies. They take the secreted wax flakes, soften them with their mandibles, and assemble them in a tube around themselves. For worker cells, they build a size that just fits: small bees build small cells, and larger bees build larger cells.
The flattened areas result where two cells touch each other. The most obvious example can be seen in soap bubbles. Wherever two bubbles touch, a flat wall is formed. Imagine building row after row of tightly packed cylinders. If you warmed them up so the walls flowed like liquid, they would develop flat sides wherever they touched, just like soap bubbles.
Researchers now believe that as the cells are constructed they are warmed by the bees’ bodies which causes the common sides to flow together and form a flat wall. Because they are closely packed, the rows form a series of hexagons that we recognize as honeycomb.
In their paper, “Honeybee combs: how the circular cells transform into rounded hexagons” (2013), B. L. Karihaloo, K. Zhang, J. Wang report that the transition from round sides to flat can happen in just seconds, depending on the temperature of the wax.
Some of the most compelling evidence for this theory can be found not in the perfectly-shaped cells but in the imperfect ones. For example, wherever the cells are not so tightly packed, such as at the intersection of worker cells and drone cells, you can see many other shapes. Four- or five-sided cells are not uncommon in this area as are cells with random shapes and cells stretched in odd ways in order to meet another cell.
Also telling are the shapes of supersedure cells and swarm cells. Since queen cells are built separately and do not touch other cells, they remain cylindrical. Even queen cells that are started on hexagonal foundation soon depart from the embossed shape and become cylindrical.
In nature, honey bees are not the only insect to build hexagonal nests. Some of their kin, including various wasps, also build hexagonal cells—proof that the hex shape is not exclusively a honey bee thing.
Honey Bee Suite