Yes, I agree with you MoonStar!!!
My cat was there for 17 generations - just changed on this one for a bunny - but I'll be back for the cat in no time (I have 2 in RL, so I can sty away from them on the game too!)
And another nice thing, besides interaction, would be the possibility of having 2 pets at the same time.

And have pet things in the house, like a litter box for the cats that you have to clean once in a while, for instance.
