unknown bee

unknown bee

Observation - unknown bee. Description: These bees have a nest in some open sandy soil in a raised flower bed. There is more than one bee using the nest as two arrive and leave in quick succession, so I think this is a social bee rather than a solitary one. Or do they share nest sites if ther

These bees have a nest in some open sandy soil in a raised flower bed. There is more than one bee using the nest as two arrive and leave in quick succession, so I think this is a "social bee" rather than a solitary one. Or do they share nest sites if there isn't suitable habitat available?