The most popular belief today is that UFOs are spaceships piloted by aliens from outer space.
But another good theory which never gets as much press is that which says UFOs may, in fact, be right here from earth. Instead of being Extraterrestrials, UFO aliens might be Ultraterrestrials -- a species that has always been here, which evolved on earth along with homo sapiens, but which represents a species far superior.
These Ultraterrestrials are so superior to us it's almost impossible for us to comprehend their existence. All we know of them are fleeting glimpses of lights in the sky, occasional bizarre encounters between human beings and so-called aliens, and other unexplained phenomenon.
Think of how a group of monkeys in the wild perceive human beings. Because their own level of consciousness is so limited, they cannot comprehend that we humans are beyond being just another kind of animal. They may see a jet or a helicopter or a car, but to the monkeys, nothing in their consciousness can explain these amazing things. A monkey may think of an airplane as some kind of magical giant bird. They relate to it with the level of understanding they have about their environment. The speculation of the monkey, at best, is a crude idea about the total truth of an airplane, and the fact it represents entire levels of consciousness that are so advanced, they are literally invisible to monkey mind.
Now think of a human being who encounters a UFO. To us a UFO seems to be some kind of flying, mechanical aircraft -- but the true nature of the UFO may be as different from a spacecraft as a bird is from an airplane. Like the monkey, we just don't have the advanced levels of consciousness we need to comprehend the true nature of a UFO.
As humans, we make the naturally egotistical assumption that we are the species at the top of the heap -- we see ourselves as the peak of achievement of evolution. We even make the bold claim that God, the supreme architect of the entire universe, created us in his own image!
But it's not a big leap to consider that we are just another link in a vast chain of species, many which are below us, and some which may be above us.
Source: conspiracy archive.com