Mining Bees

How to identify it

• Nests are easy to spot as small cones of soil with a hole in the middle, the entrance to each nest.^[1]
• Hundreds to thousands of nests can be built close together, though each nest holds only one female.^[1]

Look-alikes

Where it lives

Penn State notes mining bees are among the most abundant ground-nesting bees in the northeastern US, and Pennsylvania alone has at least 438 bee species.^[1]

US map: public records from 45 states since 1990 (GBIF). View the map

Biology and life cycle

Ground-nesting spring bees are active for about 6 to 8 weeks, and about a third of Pennsylvania's bee species emerge in March and April.^[1]

Most prefer loose, exposed soil on south-facing slopes, which warm earlier in spring.^[1]

They pollinate native plants and crops such as apples, pears, cherries and blueberries.^[1]

Damage and signs

• They don't damage lawns or homes; their nests are common in backyard gardens.^[1]

Health risk

Females have a stinger but aren't aggressive; they won't try to sting unless handled or stepped on.^[1]

Control

Prevention

Penn State strongly recommends avoiding chemicals; if control is absolutely necessary, water the nesting area to encourage the bees to nest elsewhere.^[1]

Common questions

What are the little dirt mounds with holes in my lawn in spring?

Often the nests of mining bees, which build small soil cones with a hole in the middle.^[1]

Will ground-nesting bees sting me?

Rarely. They aren't aggressive and won't try to sting unless handled or stepped on.^[1]

Sources

1. Penn State Extension, “Spring Bees: Who Are They and Where Do They Live?.” extension.psu.edu/spring-bees-who-are-they-and-where-do-they-live (accessed 2026-10-06)
2. iNaturalist, “Andrena taxon page (order and family).” www.inaturalist.org/taxa/57669 (accessed 2026-10-06)