Nature:
Why honeycombs form hexagonal grids has been debated for
millennia: It has never been clear whether the shape is
determined by the bees or by natural processes. To find
out, Bhushan Karihaloo at the University of Cardiff in the UK
and his colleagues interrupted the formation of a new honeycomb
to take pictures of the structure in the formative process.
They found that the newly formed cells were actually circular
in shape, but that over time, the walls settled into hexagons.
When the bees create the cells, their body heat warms the wax
to the point that it can flow. As a result, the surface tension
and the pressure between adjacent cells force the wax to take a
shape that minimizes the total wall area. And for arrays of
regular, simple polygons—which can only be formed from
triangles, squares, and hexagons—hexagons have the
smallest wall area. Whereas bees may play an active part in
maintaining the arrangement of the structures, it appears that
the individual cells are shaped purely by surface
tension.
