I'm not sure what kind they are exactly, but here in New England they literally buzz from July to October. Rose of Sharon gets the humming birds to our yard.
I would add, as someone who read "The Lightning Tree" but not recently, it is recognizable as the same story with quite a bit added. It's a nice novella and I like Rothfuss's turn of phrase, but it doesn't have the meat of the main story or the whimsy of "Slow Regard of Silent Things"
Also it is a little weird that the author's note starts with "You might not want to buy this book", of course I got it out of the library so I guess I can't complain.
Had a moment like that with our Tuxedo this afternoon, cheers, enjoy the moment. Hope yours had as happy an ending as ours did.