At noon today it was sunny and warm and these bees became increasingly common as the afternoon wore on, even when the clouds covered the sun and the wind turned cooler. Claudia and I watched them for a long time as they hovered over the bare soil and occasionally entered the nest sites that are scattered across a wide area where the soil is bare. Naturally, along with these Andrenids, we saw some Nomada bees, which are parasitic in the nests of the former.