Mining bees

Description:

Small, solitary, black bee that excavates individual nesting burrows maybe 6 inches down leaving small mounds of clay soil that are seen around each hole. You can walk right through the swarm and never get stung they are not aggressive. They are good pollinators, size maybe 1/2 inches, females excavate during the evening hours and during the day, the active females collect pollen and nectar to carry back to the nest to form a "ball" 1/8 to 14 inch in diameter that is placed within a "cell" excavated in the side of the burrow. A single egg is laid upon the pollen ball. After hatching, the larva feeds on pollen and develops within the cell into a new generation of bees. The new generation emerges the following year in March or April. At this time, mating takes place and bee activity begins to pick up as the nesting cycle resumes. Though adult bees feed on nectar, none store honey as such. They prefer nesting in areas with morning sun exposure and well-drained soils containing little organic matter. Burrows are excavated in areas of bare ground or sparse vegetation.

Habitat:

Urban schoolyard

Notes:

It is scary to see so many but they are valuable pollinators, not aggressive and should not be destroyed. They comes for maybe 4 weeks every year in either March or April, dig thousands of nests in this south facing sunny clay soil slope; one egg per hole; 1000's like a whole city in close proximitySome of these bees line the burrow with a water-proofing secretion for protection from moisture