Yesterday I saw a leaf cutter bee hovering in front of a mud dauber nest. The mud dauber nest was abandoned last autumn, and is now available. If this is a regular thing, I'll be getting some pictures of it in the near future.

Pictured here is a leaf cutter bee, Osmia ribifloris ribifloris, in the foreground, and a mining bee, Adrena sp. in the background.

Osmia ribifloris