Bees, recognized for their role in pollination, exhibit diverse nesting behaviors beyond the communal hives commonly associated with honey bees. Understanding where these insects build their homes provides insight into their life cycles and contributions to ecosystems.
Yes, Some Bees Nest in the Ground
A significant number of bee species construct their nests underground. Approximately 70% of the world’s bee species utilize soil for nesting, making it the most prevalent nesting substrate. These ground-nesting bees are typically solitary, meaning each female builds and provisions her own nest independently. While individual females manage their own nests, many may choose to nest in close proximity, creating visible aggregations that can sometimes appear like a colony. These solitary ground nesters are generally not aggressive and are unlikely to sting unless directly provoked.
Bumble bees also nest underground, often utilizing pre-existing cavities such as abandoned rodent burrows, dense grass, or other sheltered spaces. Unlike solitary ground-nesting bees, bumble bees are social insects that live in colonies with a queen and workers. Their social structure distinguishes them from solitary ground-dwelling species.
Meet the Ground-Nesting Bees
Several types of bees commonly nest in the ground. Mining bees (genus Andrena) are among the earliest to emerge in spring, often found in sandy soils or bare patches of ground. These solitary bees excavate vertical tunnels with short side chambers where they lay individual eggs and provision them with pollen and nectar. While each female has her own nest, they frequently nest in aggregations, giving the appearance of a larger community.
Cellophane bees (genus Colletes), also known as plasterer or polyester bees, are another common ground-nesting group. These solitary bees are recognized for their unique ability to line their underground brood cells with a waterproof, cellophane-like secretion produced from their abdominal glands. This lining protects the developing larvae from moisture and fungi. Cellophane bees often nest gregariously in sandy soils, with individual nests sometimes numbering in the thousands within a single area.
Digger bees (genus Anthophora) are robust, often hairy bees that construct nests in the earth, sometimes in level ground or vertical banks. Many species build distinctive turret-like structures, called tumuli, at their nest entrances using excavated mud. While solitary, digger bees are frequently gregarious, forming large aggregations where many individual nests are built close together. These bees are efficient pollinators.
Understanding Ground Nests and Their Inhabitants
Ground-nesting bees choose to construct their homes underground for several reasons, including stable temperatures, protection from predators, and access to specific soil types. They typically prefer well-drained, sandy, or loamy soils with sparse vegetation, though some species adapt to hard-packed or clay-rich areas. The structure of these nests generally involves a main vertical tunnel, which can range from a few inches to several feet deep, with various side chambers branching off. Each side chamber typically contains a single egg and a provision of pollen and nectar for the developing larva.
Solitary ground-nesting bees are notably non-aggressive and rarely sting unless directly handled or stepped on. The males, often seen flying near nest entrances, do not possess stingers at all. Do not confuse these beneficial bees with ground-nesting yellowjackets, which are social wasps that aggressively defend their nests and have a single, busy entrance with many individuals entering and exiting.
These bees are important pollinators for many plants, including various crops and wildflowers. Coexisting with ground-nesting bees typically involves leaving their nests undisturbed. They are active for a relatively short period in the spring and then disappear as the larvae develop underground. Increasing lawn density or watering the area can encourage them to move elsewhere if their presence is undesirable, but using pesticides is not recommended.