It did not take long to find it back, online. That’s all I remembered (I had read it in a book with short SF-stories).
I knew it had the word “Phoenix” in the title. It always “stuck to my mind”, I never forgot the zest of it. While reading a blog of a PA-member (Bruce Charlton) with that very title – Mouse Utopia – I was reminiscing about a short science fiction story I read long time ago.
“Mouse Utopia” was a sort of new concept for me.