I've not had this with my cat but when I took my dog to the holistic vet that is also an empath- Keegan kept staring at the door staring UNDER the door cocking her head to the sides, i looked at the vet and she was staring out the corner of her eye murmuring something saying ' do you see the kitty??' yea, its a kitty, you see it don't you.......
there happened to be a cat in the backroom meowing its head off and then she commented its not the one in the back we haven't touched him yet!!