Most of my hummers have moved on! Still have a couple of brave ones, but the carpenter bees and bumble bees seem to want to chase the hummers. Not that the carpenter bees feed out of the feeders, but when the hummers come in to feed, the carpenter bees run up to them like them wanting to fight, and the hummers fly off, unfed.
The carpenter bees that I see are all male bees, i.e. white face (won't sting you either). I could spray insectacide and kill off the bees, but they're great for polinating the garden. Besides, I don't want to also kill off everything in site...
Guess I'll just leave nature to resolve the issue.