Alveoli are very thin-walled cells composed of wax (90%), propolis, and pollen (10%) built by wax bees from mid-March to mid-July. Used by the bees to store honey, brood, and pollen, their perfect hexagonal shape constitutes a deformation of their original circular build. Under the effect of heat, which can go up to 113°F (45°C) inside the hive, and in accordance with the principle of viscoelasticity, the cells compress together, the wax melts, and angles begin to form mechanically.