Every time I've had a cat who was near its time to die, My house has been paid a visit by a "strange" cat, that is, one none of us had seen before (different appearance each time), who would sit and make mournful noises outside a window or door. And after my cat's passing, the "strange" cat would come no more. This happened most recently this past November. In six years of living where we do, it's the only time a "stray" has even been seen in our neighborhood. I don't try to explain phenomena such as these. I just marvel at the Mystery.