I love those things. There is not much more heartwarming than watching them light up in the twilight. I hardly ever saw them while growing up on the farm. But when we'd go visit my grandfather in Mississippi I'd see tons of them and I'd catch them and put them in jars. (I hope I eventually let them out.)
It had to have something to do with all the pesticides we used on our farm. And of course when I moved away to Los Angeles I never saw them. I'd almost forgotten about them until we moved to Austin.
Between the fireflies and the cardinals, I'm in heaven.