Apparently, they use human males to give "samples" which are then used to impregnate any given female host, whether it be Gray or human. Preferably human, but... no. The reason that they impregnate humans to make humans is just to study more about embryology, as they have a limited comprehension of anything and everything human. They either clone themselves through unknown methods, or live for a LONG time. They sustain nourishment by soaking up vitamins in a supplemental bath of sorts. The Grays also have about four eyelids, the outermost being the large black shade which is commonly reported, and the inner eye itself is unimaginably... idk.
