Mysterious drones have been showing up in the skies above New Jersey and other states for weeks, confounding residents and prompting lawmakers to call for more answers as to what exactly is going on. 

Since mid-November, the drones have been lighting up night skies with no real explanation. While plenty of questions remain surrounding the phenomenon, here is what we do know. 

When were the drones first spotted?

The drones were first spotted in New Jersey on Nov. 18. They appear to show up in the late hours of the night, though it is not clear if they are present every single night. 

A senior official briefed on the New Jersey drone sightings told NBC News there have been reports of sightings every night except Thanksgiving and that there have been "little to no" reports of drones during the day. 

NBC News has been tracking reports of possible drone sightings, mostly in New Jersey, since at least Dec. 3. 

Where are the drones being spotted now?

The drones were first spotted in North Jersey, but now appear to be popping up throughout the state. NBC News has also tracked possible drone sightings in New York, Maryland and Florida. 

FBI Baltimore said in a statement that it was aware of sightings of possible drones in Maryland and Delaware. 

Where are they coming from and why are they there?

These remain the biggest unknowns, with officials unable to publicly pinpoint where the mysterious objects originated or explain exactly what they are doing there.

In a joint statement Thursday about the reports of drones in New Jersey, the FBI and Department of Homeland Security said they "have no evidence at this time that the reported drone sightings pose a national security or public safety threat or have a foreign nexus.”

The agencies said they are working with New Jersey State Police and its federal partners to investigate the situation.

The statement said the agencies have "not corroborated any of the reported visual sightings with electronic detection."

"To the contrary, upon review of available imagery, it appears that many of the reported sightings are actually manned aircraft, operating lawfully," the statement said. "There are no reported or confirmed drone sightings in any restricted air space. "

The Pentagon has said they are not owned by the military and that they are not coming from an Iranian "mothership" off the East Coast, as suggested by Rep. Jeff Van Drew, R-N.J.

In a statement to NBC News, the U.S. Secret Service confirmed it “does not currently have any unmanned aerial systems operating in or around New Jersey or New York.”