for a while a believe they were from out there, until more evidence showed they had been here as long as man could remember and leave clues. There is The Bible that give hints
they fly to and fro through the earth. Who did not die in the flood that killed most of mankind? It was not mankind! It was the fallen, the one from heaven came, they corrupt Creation so bad God cleaned it, but it didn't stop there, they kept it up after the flood, just read it and other text and you will see they have been here a very long time and not to the betterment of mankind!