I've been going crazy trying to find the name of a book. All I remember is that is featured multiple alien races.
The races were best described as:
Rat/mole-like creature that lived underground.
Large crab-like creatures
Floating/flying balloon-ish beings
Shark-like flying predator.
I think they were at war with each other, or fighting each other. Some/all of the aliens were highly intelligent and communicated with human visitors.
I think the story starts on Earth, and maybe actually ends on Earth with a nuclear explosion?
I know this sounds random and rambling, but it was quite a few years ago.