These bees nest in gardens with loose earth, like in my front yard. I found 3 nest tunnels in a small area, each measuring about 5 cm across. This is the bee that entered the tunnel about 30 seconds later. When I came back about 2 hours later to measure the tunnel and mound, I found that it had been sealed with earth. The earth plug was noticeably drier and lighter than the surrounding wetter soil.

I am assuming the species is andrena, but placing it here in the subfamily for confirmation.