"Are the humans ever a threat to the aliens living on Earth? Put two or more different races together in one place and there's bound to be tensions, I'd imagine. Some of the humans must be less than thrilled to see their planet welcome in refugees from other worlds."

Narvin didn't know human biology terribly well, but he knew Earth history, which to Narvin seemed be a fight between the humans who loved novelty and sought out new people and places, and the humans who raged whenever new humans showed up in their territory.

"In my universe and era, the humans are one of the Temporal Powers. Virtually none of them are pure homo sapiens any more, however. They've been...ah...mingling around the universe for a great many of their generations."