Fireflies? Are you talking about lightning bugs? You damn Yankees.
Kidding aside, this really was lovely and wonderful to watch. I don't remember the first time I saw fireflies, but I think this comes as close as anything could to bringing back that sense of wonder.
And it also brought back to me the evening I was taking a friend who'd spent most of his life in Britain back to my house. He stopped on the sidewalk and asked, with a trace of fear, "Why are there little lights all over your yard?" And he was delighted to learn that they were insects, and not something sinister, like will-o-the-wisps.