Awe! That is such an awesome story!
Having run a rescue home for so long, I totally believe they communicate.
What I see is many different pets from different, albeit abusive, households. So, when they end up in my house, not all of them share the same language. But they quickly form a simple one. And as they are together longer they share the common language of the "land" that is my house.
And it seems to bridge the species gap as well- cats and dogs and lizards all seem to understand each other after they have been under my roof a while... It's a pretty cool phenomena to witness