We saw the same from a neighboring camper last February
I got my own
I have used it 5-6 times this past summer and again just two weeks ago in FL... everyone totally enthralled of the "glow worms" in the trees... of course you have to aim it properly and hide it behind something and talk about the proper humidity and temperature and the glow worms might appear...
Lots of fun!
If the wind is blowing slightly and the leaves are moving then it appears the fireflies are moving.