Bees create arrays of hexagonal cells in a beehive. However, the shape of each cell is not a hexagonal prism as you might expect because the bottoms of the cells are not flat. Bees make two layers of comb back to back. The two layers are offset so that the center of a cell on one side lines up with the point where three cells meet on the other. In this arrangement, the ends of the cells form half of a rhombic dodecahedron!