With the use of very tiny piezoelectric actuators that draw very little current I believe it is now possible to create these very tiny flying drones.
This is a tiny fiber optic camera. One day soon I believe there will be chip sized drones! Likely based on the dragonfly using the tiny battery cells already available. The tiny drone will be based on carrying it's battery payload.
I just thought it might be interesting to see how tiny drones might really get in the near future. I'm not talking about 50 years into the future, I'm talking 5 maybe 10 years ahead!
So before you swat that next bug you might want to check it out first! LOL soon it could be a tiny drone and not really a bug!