"Just one. They can travel to other planets in special meat containers, but they can't live on them. And being meat, they only travel through C space. Which limits them to the speed of light and makes the possibility of their ever making contact pretty slim. Infinitesimal, in fact."
"So we just pretend there's no one home in the universe."
"That's it."
"Cruel. But you said it yourself, who wants to meet meat? And the ones who have been aboard our vessels, the ones you have probed? You're sure they won't remember?"
"They'll be considered crackpots if they do. We went into their heads and smoothed out their meat so that we're just a dream to them."
"A dream to meat! How strangely appropriate, that we should be meat's dream."
"And we can mark this sector unoccupied."
"Good. Agreed, officially and unofficially. Case closed. Any others? Anyone interesting on that side of the galaxy?"