So, like John von Neumann, the von Neumann machine, Dr. von Neumann was, I'm quite sure, involved in studying this when he was alive back in the 40s and 50s.
And he conceived of something that we call a von Neumann machine, which is basically a ship that contains the complete expression of a species.
And I've even thought that maybe they are a von Neumann machine who arrived at a planet that contained an unexpected presence, us.