Bumble bees are important pollinators for ecosystems. Understanding where these insects make their homes offers insight into their biology and the environments they inhabit. Their distinct nesting habits provide a glimpse into their annual life cycle and social organization.
Common Nesting Environments
Bumble bees typically establish their nests in existing cavities rather than excavating their own. Abandoned rodent burrows are a common choice for many species, providing a ready-made, insulated, and protected underground space. These underground locations offer protection from predators and adverse weather conditions, including heavy rainfall and wind. The queen may use the existing soft lining material for her new home.
Beyond subterranean dwellings, bumble bees also utilize other sheltered spots. Some species prefer to nest on the surface, choosing dense grass tussocks or mossy vegetation. Compost heaps provide warmth and insulation as suitable nesting sites. Additionally, bumble bees can be found nesting in unexpected places within human structures, such as bird boxes, wall cavities, roof spaces, or insulation. Their adaptability allows them to find secure environments for their colonies.
The Structure of a Bumble Bee Nest
Once a suitable location is chosen, the bumble bee nest takes shape. Unlike the highly organized, hexagonal comb of honeybees, a bumble bee nest appears less structured and somewhat “messy.” The queen produces wax flakes to construct small, round wax pots. These pots store nectar and pollen for the queen and her brood.
Brood cells, also made of wax, are where the queen lays her eggs. These cells are arranged irregularly within the chosen cavity. As larvae develop, they spin silky cocoons, which become part of the nest structure. The queen lines the nest with soft materials like dry grass or moss, creating a warm and insulated chamber for her eggs and larvae. This insulation maintains a stable temperature, essential for brood development.
Life Within the Colony’s Home
Life within a bumble bee nest revolves around the queen and the colony’s annual life cycle. In spring, a single queen emerges from hibernation and initiates a new nest. She forages for food, builds her initial wax pots, and lays her first batch of eggs. The queen then incubates these eggs to maintain the optimal temperature for development. She continues to forage and care for the brood until the first generation of female worker bees emerges.
Once worker bees are present, they take over foraging for nectar and pollen, feeding larvae, and maintaining the nest. Some workers remain inside to clean, guard against predators, and regulate the nest’s temperature. The queen, now focused on egg-laying, rarely leaves the nest. As the colony grows, it stores resources in wax pots, and new generations of male bees and future queens are produced. The colony declines by autumn, with only new queens surviving to hibernate and begin the cycle.