A Kim tale:

Last night at the 2am feeding, she had settled and was purring away. BTW, she insists on being held. She stopped, looked over my right shoulder at shoulder height and stared. And STARED. And kept staring, turning 90 degrees slowly to look over left shoulder and back again. I looked but could see or feel nothing. Slow, horizontal spider? Imagination?

Or a ghost? Spectral being? That bothers me less than a microscopic spider. I've live in a haunted house before, and have seen cats concentrate on the invisible before, so that idea that they can see spectral beings does not faze me.