okay sorry for double posting here, but i'm sure that unless your people have already experienced the effects of keeping one alive, that they wouldn't know that they could even do it. As this would be the first time most had been in contact with them, from what i've read in the bios.
And reading from the lore, they can only contact each other, and not read minds. think of 'the calling' like a collective mind. but just trying to clear a little confusion in that little thing, because not having anyone know would have made a fun little twist in the plot.