For many people, the word “bee” conjures the image of a honeybee hive, a large community housed in a wooden box or a tree hollow. This popular image, however, only represents a small fraction of the world’s bee species. Bee habitats are highly diverse, reflecting the varied lifestyles of these pollinators, most of which do not live in colonies at all. The location a bee chooses to raise its young is a defining characteristic of its species, ranging from complex, multi-generational structures to simple, individually-dug burrows. Understanding where different bees live reveals the depth of their ecological roles and the specific environments they require to thrive.
Large-Scale Social Colonies
A small minority of bee species, including Honeybees (\(Apis\) species) and Bumblebees (\(Bombus\) species), form large, organized colonies characterized by a reproductive division of labor. Honeybees construct intricate, permanent nests within sheltered, darkened cavities like tree hollows or rock crevices. The internal structure of a honeybee hive is built entirely of beeswax, which workers secrete and mold into parallel sheets of hexagonal cells called comb. These wax cells are used for both rearing new individuals and storing honey and pollen.
Bumblebees also exhibit social behavior but build less complex, temporary nests that do not typically survive the winter season. These colonies are much smaller, often peaking at a few hundred individuals, compared to the tens of thousands found in a honeybee hive. A queen bumblebee initiates her nest in an existing cavity that provides insulation, frequently utilizing abandoned rodent burrows or dense tussocks of grass. The interior is a rudimentary collection of wax pots for storing nectar and clusters of wax brood cells for the developing young.
Solitary Bees that Nest Underground
The vast majority of bee species live solitary lives and choose the ground as their nesting site. These bees, which include Mining Bees (\(Andrena\)) and many Sweat Bees (\(Halictidae\)), do not share labor or raise their young communally. Instead, a single female bee undertakes the entire process of excavating a nest, collecting provisions, laying eggs, and sealing the cells. They prefer areas with bare, well-drained soil that is loose or sandy, which makes the digging process more manageable.
The architecture of a subterranean nest generally consists of a main vertical or angled tunnel extending into the earth. Along this central corridor, the female digs lateral tunnels, each terminating in a single, distinct brood cell. Inside this sealed cell, the female places a mixture of pollen and nectar, known as a pollen loaf, and lays a single egg on it. She then lines the cell walls with a glandular secretion that helps to waterproof the chamber. While these bees are solitary, they often nest in large aggregations, with hundreds of individual burrows clustered closely together in a suitable patch of ground.
Cavity and Wood-Nesting Species
Solitary bees nest above ground in pre-existing or self-excavated cavities. Mason Bees (\(Osmia\)) and Leafcutter Bees (\(Megachile\)) are prime examples of this group, relying on natural or artificial tunnels such as hollow plant stems, abandoned beetle holes, or man-made bee hotels. The female divides the length of the tunnel into a linear series of cells, each provisioned with a pollen and nectar mixture for the developing larva.
The material used to partition these cells gives the bees their common names. Mason bees use mud or clay to construct the walls and seal the entrance of the tunnel, much like a mason uses mortar. Leafcutter bees, conversely, use precisely cut, semicircular pieces of leaf to wrap the food and egg, creating a cell that resembles a small cigar.
Carpenter Bees (\(Xylocopa\)) are an exception among cavity-nesters because they bore their own tunnels into soft or dead wood, rather than using pre-existing holes. These bees create a smooth, clean gallery in the wood, then use wood pulp particles to create partitions between their brood cells.