After some research, I quickly discovered using the flash to take hummingbird pictures requires a short burst of light (1/5000 - 1/15000 of a second) to freeze the wings and minimize ghosting. Setting my flash to Manual mode, I reduced the power to 1/8. I'd have preferred to go to 1/16, but it was too late in the evening. The Ruby-Throated Hummingbird is brave, so I moved to the outside of the house - about 8-10 feet away from the feeder. These photographs are looking much better than the first try. Many of the sites recommend multiple flashes, that is an experiment for another day.
Last shot before bedtime.