Honeycomb

A honeycomb is a mass of hexagonal waxcells built byhonet bees in their nests to contain their larvae and stores of honey and pollen.
The axes of honeycomb cells are always quasi-horizontal, and the non-angled rows of honeycomb cells are always horizontally (not vertically) aligned. Thus, each cell has two vertical walls, with "floors" and "ceilings" composed of two angled walls. The cells slope slightly upwards, between 9 and 14 degrees, towards the open ends.
The closed ends of the honeycomb cells are also an example of geometric efficiency.