1. usually have a triangular shape defined;
2. Its technology allow them to be virtually invisible to cameras and radars common, much less appear with a dot of light so bright and flashy in the night sky;
3. their lights are fixed and are not installed by mode to circumvent the vehicle, much less - lights on, what would be completely contrary to the purpose of espionage and patrol;
4. their speed, although remarkable, do not compare to the behavior of UFOs plasma;
5. are not metamorphic;
6. drones don't perform all movements and displacements possible to UFOs-plasma.