Honeycomb hexagonal shape appears to be natural, not designed

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.