Some further tribulations of writing science fiction:

1. How do you even name your characters, if they're from a species that doesn't even use sound to communicate? In most science fiction of this sort, they'll make up some random string of letters, like "Q'flth", which is just cheating to my eyes. Or, they'll have some quasi-Native American sounding name, like Speaker For Ancestors or StarToucher or some other such nonsense. It's a real problem.

2. Similies and metaphors are pretty much right out. You can't very well say a character has, I don't know, skin like tissue paper if there's no tissue paper within fifty light years. Just about everything you'd want to compare something to is man-made or earth-specific.