Oh, I did not know they can be killed by the evil bunny when we do not play the lot. I just saw the rabbit head in the ghost of a sim who recently died (from old age I assumed).
So the game will actually pick a random death whenever a non played sim dies? I never see younger sims die on lots not played, so they are all up around 80-85 years old.
And another detail, why is the rabbit head showing at some times, but at other times - same ghost - it is not there.
Also see they keep changing colors, at least some of them do. In the past it was the color that said something about cause of death, but that must have been replaced with those in-torso symbols at some point. I never focused a lot on ghosts in my game, so I will have missed most changes like that.