Many long times ago I had a rat named Phfft. He was a free range rat, having run of the house. He'd eat out of the cat food bowl with the cats, trade sniffs with the dogs, come when you called him, sometimes, or tapped on the floor three times. He spent a goodly amount of time under the sofa in the living room.
He fathered many a baby and, as you can see, is fondly remembered even now, years after he bit the big one.
Sorry for your loss.