Bumble bees are important pollinators, contributing significantly to ecosystems and food production. Understanding their nesting habits offers insights into their lives, aiding in their conservation.
Common Nesting Environments
Bumble bees primarily establish their nests in existing cavities, as they do not excavate their own. Many species prefer underground locations, frequently utilizing abandoned burrows of rodents. These pre-existing tunnels provide a sheltered space, often complete with insulating materials left by the former occupants. Natural cavities formed by tree root systems or rock arrangements can also serve as suitable subterranean homes.
Surface-level nesting is also common for bumble bees. They often choose dense grass tussocks, where the thick vegetation offers concealment and some protection. Piles of compost, leaf litter, or debris under sheds and outbuildings provide additional ground-level options. These sites offer readily available materials for nest construction and insulation.
While less common, some bumble bee species will nest above ground. These locations can include disused bird boxes, hollow spaces within trees or logs, and even insulation in wall cavities or roof spaces of buildings. Bumble bees are adaptable, seeking out any suitably sized, dry, and protected void that meets their needs.
Factors Guiding Nest Choice
The selection of a nesting site by a queen bumble bee is guided by several environmental factors. Shelter and protection from predators and harsh weather are necessary. The chosen location must offer a stable and moderate temperature, avoiding extremes of heat or cold.
Dryness is another factor, as bumble bees avoid damp areas. Queens often prefer well-drained soil. While proximity to foraging areas is beneficial, it is not the sole determinant, as bumble bees are strong fliers.
An undisturbed location is also important for a bumble bee colony. Queens seek out areas with minimal human or animal activity to reduce the risk of disturbance or destruction. This combination of shelter, temperature regulation, dryness, and seclusion contributes to the queen’s decision when selecting her nest.
Inside a Bumble Bee Nest
A bumble bee nest, unlike the highly structured hives of honey bees, often appears less organized internally. The queen utilizes available materials to line her chosen cavity, such as moss, dry grass, or fur from abandoned rodent nests, creating an insulated inner chamber. This material helps maintain a stable temperature for the developing brood.
Within this insulated space, the queen constructs irregular wax pots. These pots serve as storage vessels for nectar, which is processed into honey, and for pollen, providing food resources for the colony. The queen also creates wax brood cells where she lays her eggs.
As the eggs hatch, the larvae develop within these cells, feeding on the stored pollen and nectar. After growing, the larvae spin silken cocoons to pupate before emerging as adult bumble bees. A typical colony begins with a single queen, and as workers emerge, they take on tasks like foraging and nest maintenance, allowing the queen to focus on laying more eggs.
Coexisting with Bumble Bee Nests
Identifying bumble bees is often possible by their fuzzy, rounder bodies, distinguishing them from wasps or honey bees, which have smoother, more slender forms. Bumble bees are generally docile insects and will only sting defensively if they feel directly threatened or their nest is disturbed. Female bumble bees can sting multiple times, but males do not possess a sting.
If a bumble bee nest is discovered, the recommended approach is to observe it from a safe distance and leave it undisturbed. Most bumble bee colonies are annual, meaning they only last for a single season, typically from spring to autumn. By late summer or early autumn, the colony will naturally decline, and only new queens will survive to hibernate and start new nests the following year.
Bumble bees do not cause structural damage to property since they utilize existing cavities rather than chewing through wood or other materials. Therefore, moving a nest is generally not recommended unless absolutely necessary, and should only be attempted with expert guidance.