There was another story, forgotten the title and author, in which a similar thing happened. These aliens give mankind untold benefits bringing on a golden age etc. etc. They do this because they find humans so similar to them.
Anyway, one day this alien meets a bunch of hunters out shooting and is really pleased to hear that the combined space fleets of many Earth powers are preparing to explore beyond Pluto because his people are there waiting. he asks if he could join their hunt because his people hunt also.
At that point he sees some ducks and aims his rifle at them only to be told that hunters don't shoot at sitting ducks. He puts his gun up, smiles and says - Another similarity, neither do we.
It ends there but I think we can all guess what was about to happen.
