Government Whistleblower Says There Was a Secret Pentagon Program to "Trap" UFOs

[Ninurta]

John Keel theorized this way back in 'The Mothman Prophecies'.  he called them ultra-terrestrials.

just call them demons.  always teasing but never providing any *real* evidence, leaving a trail of fear and frustration.
one of the chapters was titled 'games nonhumans play'.

I too think it's much more likely that they are "interdimensional travelers" - or "demons" for short (hat-tip to Robert Lynn Aspirin's "Myth" series, where "demon" is just a shorthand version of "interdimensional traveler") than it is they are actual beings from another planet in this space or universe. It just seems far more likely to me that they are merely phase-shifting to travel across adjacent dimensions than it is they are traveling distances too vast to comprehend and too far to be traversed in a single lifetime, or even generations of lifetimes.