Ground bees, also known as mining or digger bees, are solitary insects that play a valuable role as native pollinators, particularly for early spring flowers and fruit trees. While generally non-aggressive, their tendency to nest in residential lawns and gardens can concern homeowners. Preventing ground bees from nesting focuses on modifying the soil conditions and landscape features that attract them. Non-lethal methods focus on making the ground undesirable for their annual nesting cycle.
Identifying Ground Nesting Bees
Ground bees are primarily solitary, meaning each female constructs and provisions her own nest tunnel, unlike the large, social colonies of honeybees or wasps. The most common types are often from the genus Andrena, known as mining bees, and they are active for a short period in the spring, typically four to six weeks. Their presence is visible through small, volcano-shaped mounds of excavated soil, each with a single, pencil-sized hole in the center.
These bees are docile and will not sting unless physically threatened or accidentally stepped on. A key indicator is their solitary behavior; even when multiple nests are clustered, each hole represents a separate bee. They are distinguished from aggressive, social ground-nesting wasps, like yellow jackets, by their hairy bodies and lack of a narrow “waist.” Yellow jackets are hairless, have more vivid yellow and black markings, and use a single, shared entrance for an entire colony.
The presence of ground bees is a sign of a healthy ecosystem, as they are highly effective pollinators for early-blooming plants. Their brief activity period and non-aggressive nature support using humane deterrence methods over lethal chemical treatments.
Environmental Changes to Deter Nesting
Ground bees specifically seek out patches of bare, dry, well-drained, and lightly compacted soil to excavate their nests. Prevention efforts are most successful when they begin before the nesting season, typically in the early spring. Modifying the soil surface to eliminate these conditions makes the area unsuitable for burrowing bees.
A simple deterrent is to increase the soil’s moisture content in the targeted area. Ground bees avoid damp soil because it is difficult to tunnel through and offers poor protection for their larvae. Targeted watering of the affected area daily during the bees’ active season can encourage them to relocate to drier ground.
Another effective strategy involves eliminating bare earth by establishing dense ground cover. Planting turf grass, clover, or other thick ground covers creates a root structure that physically obstructs the bees’ ability to dig. Applying a thick layer of mulch, such as wood chips or straw, to flower beds and garden areas also prevents access to the soil surface. Mulch should completely cover the soil, making it impossible for the bees to start a tunnel.
Increasing soil compaction also reduces the ease of excavation. Lightly rolling the area or increasing foot traffic in bare patches of the lawn can make the soil less penetrable. These habitat modifications should be maintained throughout the spring to ensure the female bees do not return in subsequent nesting seasons.
Safe Management of Active Nests
If ground bee nests are already active, the most responsible approach is to manage the area safely until the short nesting period concludes. The adult bees are only active for approximately four to six weeks in the spring, after which the tunnels become inactive until the following year. Simply avoiding the immediate nesting area during this brief window is the easiest management solution.
For areas that cannot be avoided, temporary physical barriers can be placed over the aggregation of nests to discourage activity. A piece of lightweight netting, a sheet of landscape fabric, or a layer of straw can be gently placed over the nesting site. These temporary covers should only be used during the active period and removed once the bees have disappeared, allowing the ground to be properly treated afterward.
Once the bees are no longer active, the tunnels can be gently collapsed and filled with soil. This action, taken after the season ends, prevents newly emerged bees from reusing the same tunnels the following spring. Avoid using harsh chemical pesticides or pouring toxic liquids into the nests, as these methods can harm beneficial bees and contaminate the soil. Using strong, natural scents, like a light dusting of cinnamon or peppermint oil applied around the nest entrances, may also encourage the bees to seek an alternative site without causing harm.
If the insects exhibit aggressive swarming behavior, they are likely yellow jackets, which are social wasps. If the nest is in a high-traffic area, a pest control professional should be contacted for safe removal due to the risk of multiple, painful stings. Professionals can confirm the species and use targeted treatments that minimize risk to people and other beneficial insects.