I agree Earth is not a host. It implies some sort of invasion by us or others? Considering that we humans are just a little firmer than jello, us, as a guest, would be closer. An idea that we may never know enough to believe or dismiss the possibility that we are someone else's experiment. After all, its the sort of thing that we humans would do if we had the opportunity. But beyond that, I agree. Reverence for our home should always be paramount.