Found on southerly exposed hillside of loose soil - not quite the texture and grain size of sand but not to far off. Bees in semi-colonial group.

Adena sp.? I'm assuming based on size , behavior, and general morphology. None of these bees were aggressive while photographing. Becuase excavation of of contaminated soils needs to take place on portion s of the site the contractor is worried about getting stung - I assume that this is a bee that won't be aggressive - is this correct?