Thank you sir. I did notice horns but didn't know what to make of it. I assumed it was the same individual as there were never more than one coming or going at the same time; always one in and one out.

These are solitary, correct? Would it be likely for more than one to build a nest in the same location? One of them would have to cross the others nest in this situation and possibly standing a chance to be "packed" in by the one closest to the entrance, if it were to finish it's nest first. I suppose the males and females of this brood won't emerge until next spring(meaning I won't have the use of this hose, this year)?

Again, thank you for the I.D. and the additional info!

each female provisions here own nest and they do not share, although one may usurp the nest of another.

I notice that the flying bee seems to have stronger white hair bands than the one in the nest, and its hairs appear not as brightly colored, but perhaps this merely reflects the angle and light conditions