A Different Kind of Nest

This year, an insect has once again made a nest in our fence. This time not in the gate, but in one of the posts around the fish pond.

And this time, it is just outside my home office window. Not unlike the Phoebe nest. Although it is doubtful I'll see what fledges with this one.

I still don't know what creature makes this nest, but I suspect it is a bee or wasp. I've not been able to find this in a field guide or on the web, but that is likely a problem with what I'm searching for.

Anyways, it's nice to know this critter has survived another year.