Tiny aircraft that just eat and go

Aircraft the size of bees that get the energy they need by feeding themselves a diet of dead flies could be buzzing around the battlefields and motorways of the future, thanks to research in southwest England.
The aircraft, up to 15cm long and equipped with sensors and cameras, could have a number of uses in civilian life and modern warfare, including reconnaissance missions, traffic monitoring or fire and rescue operations.
By “digesting” its own fuel, the aircraft could become autonomous and operate without the need for refuelling, changing batteries or recharging from the mains.
Science News Daily