Most of the 5K drone reports are planes, hobbyists and stars, feds say (nj.com)

    ... Having closely examined the technical data and tips from concerned citizens, we assess that the sightings to date include a combination of lawful commercial drones, hobbyist drones, and law enforcement drones, as well as manned fixed-wing aircraft, helicopters, and stars mistakenly reported as drones. We have not identified anything anomalous and do not assess the activity to date to present a national security or public safety risk over the civilian airspace in New Jersey or other states in the northeast.[0]

TL;DR those aren't interdimensional space elves cunningly disguising themselves as conventional aircraft, they're just conventional aircraft.