Receptacles for the habitation of swarms of bees. Natural beehives are made in caves, rock cavities, and hollow trees; some subgenera of bees have exposed aerial combs. The beehive's internal structure is a densely-packed matrix of hexagonal cells made of beeswax, a honeycomb. The bees use the cells to store honey and pollen, and to house eggs, larvae, and pupae. Artificial structures for beehives have been made since ancient times. Early artificial structures were made in a conical or dome-like form using straw or the like, but now artificial beehive structures are often square boxes constructed with movable compartments for the removal of the honey.