Joe Rogan theorized that the reason behind "alien abductions" is a DMT-spike in their brains. Think about it. We know N,N-DMT is closely associated with sleeping/dreaming. And all DMT is doing is widening your creative floodgates, so if you get a DMT-spike while conscious your mind will become fully enveloped in this profound experience. Being abducted by "aliens" may just be the path your mind pursues. Others may see elves, dragons, fairies, mystical beings, what have you. Hell Shamans fully believe in the "invisible landscape"… So how do Shamans experience these "mystical visions"? Shamans simply gather vines and plants with high levels of N,N-DMT so they can make Ayahuasca brews.
And why would an alien spy on a sleeping human? Ha!
By the way, I came across a video today that might interest some of you... There are many "alien" documentaries out there, but there is one in particular that interviews ex-military people who supposedly had experience with top secret governmental-"extraterrestrial" programs... that's where I first saw the video but I honestly can't remember name of the documentary.
YouTube - USA VS UFO