There was a research paper that described AI robots the size of a toaster traveling from star system to star system (and galaxy to galaxy). It is difficult to

There was a research paper that described AI robots the size of a toaster traveling from star system to star system (and galaxy to galaxy). It is difficult to imagine how we would detect those - even if many orbited our sun. ...but if they exist, they likely already detected us and have relayed the fact of our existance.