The way an object moves in the sky can also reveal whether it's a drone or a plane, he said. Drones tend to hover, make abrupt directional changes, or move erratically, owing to their small size and agility. Manned aircraft follow smooth, linear flight paths, especially in controlled airspace, where their routes are more predictable.

The burst of drone activity lighting up the night skies above New Jersey and other states is propelling online posts and conspiracies offering up bizarre claims to explain the drone "hysteria," some involving missing nuclear material and an impending alien invasion.

Mysterious drone sightings in several East Coast states have prompted an outcry from officials seeking answers about the flying objects.

Belleville mayor Michael Melham said information the federal government has provided to mayors about drones was "not credible."