For the last month, New Jerseyans have reported odd lights in the sky at night, a rash of reported drone sightings that has attracted the attention of local residents, politicians and even President-elect Donald Trump. Concerned witnesses have described clusters of lights, saying they look like drones hovering over populated areas around the state. Now, even as sightings have expanded to New York and Maryland, government officials haven’t been able to put people’s minds at ease.   So who (or what) are behind the mysterious drone sightings?Start the day smarter. Get all the news you need in your inbox each morning. Federal authorities have tried to reassure residents that the objects don’t appear to be operating nefariously. The FBI and the Department of Homeland Security have said these sightings mostly appear to be not drones at all.   “Historically, we have experienced cases of mistaken identity, where reported drones are, in fact, manned aircraft or facilities,” the agencies said in a joint statement.  The government also said it hasn’t corroborated the sightings. New Jersey lawmakers say they believe there is more to the story than federal officials have shared publicly. More: Mystery drones are swarming New Jersey skies, but can you shoot them down? The lack of clear answers has fueled rampant speculation and sometimes bizarre or joking theories.   “The drones in New Jersey can easily be explained. Teams are clearly spying on the Jets and Giants practices which is why they have struggled this season,” former NFL kicker Lawrence Tynes said in a post on X.  “First, a Chinese spy balloon drifted across U.S. airspace for a week. Now, unidentified drones are flying over New Jersey, avoiding radar detection. Gaps in our airspace are being exploited, and because of it, the safety of Americans is at risk,” New Jersey Rep. Jeff Van Drew posted.  Here’s a look at some possible explanations for the sightings – and the evidence for or against the theories. Because the sightings aren't confirmed to be connected, it's also possible different sightings have different explanations. Is it really drones?   Government officials have said it’s likely there’s aren’t actually drones in many of the sightings. White House National Security Communications Adviser John Kirby said many of the sightings are actually of piloted aircraft flying legally.   Harry Direen, an electronic and software engineering expert at DireenTech, said he wouldn’t be surprised if people were seeing drones at first, but that once the notion of drones took hold, people assumed any aircraft they couldn’t identify was a drone.  “After what were likely valid sightings of possibly hobbyist drones, every aircraft can then become suspicious,” he said.  Hoaxes, UFOs, witches, drones: NJ is no stranger to strange happenings Kirby said during a news conference that authorities haven’t been able to corroborate “any of the reported visual sightings” — despite using “very sophisticated electronic detection technologies.”  “The FBI, DHS and our federal partners, in close coordination with the New Jersey State Police, continue to deploy personnel and technology to investigate this situation and confirm whether the reported drone flights are actually drones or are instead manned aircraft or otherwise inaccurate sightings,” the agencies said in the statement.    Foreign government surveillance?  U.S. government officials this week assured the public that the spotted aircraft do not appear to be sent by a foreign government, quashing a theory posed by Van Drew, who said the drones could be controlled by Iran.   There’s no evidence the drones pose a national security threat, the FBI and the Department of Homeland Security said Thursday. The sightings may actually be piloted aircraft operating legally, the agencies said. Also worth noting: the craft haven’t flown in restricted airspace, they said.   “To be clear, they have uncovered no such malicious activity or intent at this stage,” a joint statement from the agencies said. “While there is no known malicious activity occurring in New Jersey, the reported sightings there do, however, highlight the insufficiency of current authorities."  New Jersey lawmakers told the Asbury Park Press, part of the USA TODAY Network, said they were briefed by State Police and told authorities don’t know where the drones are coming from, and are unable to detect them.  “Listen, I hope it’s no big deal, but the federal government needs to be more truthful.” New Jersey Assemblyman Greg Myhre said.  US government drones?  Government officials including the Pentagon said the drones spotted by residents for the last few weeks are not operated by the U.S. government or military.  It doesn’t seem likely that a government organization would be flying the drones over public locations, Direen said.   “Clearly they are not being very stealthy if they are,” he said.  Kids playing a prank, or hobbyists?  Could the drones people keep seeing be someone playing a prank, or drone hobbyists just out having a good time? It’s not illegal to fly drones in New Jersey, but you have to meet certain requirements depending on the size of the drone and the reason you’re flying it, according to federal and state laws.  If that’s the case, it should be pretty easy for officials to figure out, Direen said.  “If the drones are being flown legally, the ADS-B transponder on the drone should make it easy for authorities to identify the drone and the operator,” he said.  UFOs?  Could the drones be the work of aliens? At this point, officials have given no evidence to suggest that, but also no evidence to debunk it. (And many UFO sightings are believed to have natural explanations.) “I suppose some alien kids could be flying their toy drones while their parents are busy out abducting humans and performing experiments on them,” Direen said.  (This story has been updated to correct a misspelling/typo and to change or add a photo or video.) This article originally appeared on USA TODAY: 'Drone sightings' prompt worries, but these theories could explain what's happening