Our friends the leaf cutter bees, again

These days I just see a lot of leaf cutter bees in the backyard, enjoying the cosmos flowers.
In the image above a leaf cutter bee is flying from one Klondike cosmos flower to another.
And just about a foot away from the cosmos plants is the handiwork of the leaf cutter bees.

And more...

I jjust have no idea where they are nesting, but I'm sure somewhere near.