Bees do nest in the ground, a behavior common across many species worldwide. Ground-nesting bees represent a significant portion of the global bee population, often leading solitary lives distinct from the better-known honeybee. These insects play a substantial ecological function as effective pollinators in diverse environments.
Which Bees Nest Underground
Most bees that utilize the soil for nesting are solitary species, meaning a single female performs all nesting and provisioning duties without the help of a colony. This behavior contrasts sharply with social species, which live in large groups with a division of labor. Solitary ground-nesters do not maintain a permanent hive structure year-round.
Several widespread bee families exhibit this subterranean nesting habit, including the Andrenidae family, commonly known as mining bees. These bees are typically among the first to appear in spring, excavating tunnels in well-drained, often sparsely vegetated, soil. They are highly efficient pollinators of early-blooming plants.
Another large group is the Halictidae, or sweat bees, which range in color from metallic green to dark brown. The Digger Bees (tribe Anthophorini) also construct nests in the ground, often preferring vertical banks or hard-packed soil. While the vast majority of ground-nesters are solitary, some social bees, such as certain bumblebee species, may use abandoned rodent burrows or other existing ground cavities for their smaller colonies.
Anatomy of a Ground Nest
Ground nests typically begin with a single entrance hole on the soil surface, often surrounded by a small mound of excavated dirt called a tumulus. This opening leads to a main tunnel that extends downward, often several inches deep, depending on the species and soil type. The tunnel may be straight or branched, serving as the main access route for the female bee.
Along the main tunnel, the female excavates lateral side tunnels, each ending in a brood cell. These cells are individually provisioned with a ball of pollen and nectar, which serves as the food source for the developing larva. The female then lays one egg on this provision and seals the cell shut.
This architecture differs fundamentally from the complex, multi-layered wax combs found in the perennial hives of social bees like honeybees. Ground nests are temporary structures, used only for a single season to provision the next generation. The offspring emerge the following year, and the original nest is abandoned.
Behavior and Safety Concerns
Because most ground-nesting bees are solitary, their temperament is non-aggressive, as they have no large colony or stored resources to defend. The female focuses on constructing and provisioning her individual nest cells, not defending a hive. Stinging is a last resort, usually occurring only if the bee is accidentally handled, trapped, or stepped on.
Solitary females do possess stingers, but they rarely employ them defensively against larger threats. Furthermore, the stinger of many solitary species is not strong enough to effectively pierce human skin. Males, which are often seen flying near the nest entrances, do not possess a stinger at all.
A major source of concern arises from confusing ground-nesting bees with ground-nesting wasps, specifically yellow jackets (Vespula species). Yellow jackets are highly social and aggressively defend their large, paper-like subterranean nests with mass stinging, posing a significant safety concern. Bees are generally hairier, feed on flowers, and carry pollen; wasps are smoother, more slender, and often scavenge for protein.
Observing the activity from a distance is the safest approach, as the bees are far more interested in foraging and nesting than in human interaction. The presence of ground-nesting bees generally signifies a mild, localized concentration of activity for a short period in the spring or summer, not a persistent threat.
Encouraging Coexistence
Recognizing the ecological function of ground-nesting bees is the first step toward promoting coexistence, as they are highly efficient early-season pollinators. When a nesting area is discovered, the best practice is non-intervention, allowing the bees to complete their life cycle naturally. Their presence is temporary, usually lasting only four to six weeks.
Homeowners can manage the area by clearly marking the nesting zone and avoiding foot traffic or lawn mowing over the entrances. If the presence is disruptive, a temporary barrier can be erected to divert people or pets away from the area. Applying mulch or landscaping fabric to the soil should be postponed until the nesting season is over to prevent covering the emergence holes.
Providing a shallow water source, like a dish with rocks or marbles to prevent drowning, can support their foraging efforts. The soil should be left undisturbed during the active nesting period to ensure the next generation can successfully emerge the following year.