Blaze, the action cat of the house, has been chasing non-existent the last few days. She'll sit there, then start staring at a point in the middle of the floor/couch/bed/wherever, she'll then assume pouncing position, engage buttwiggle, and then launch herself at whatever it is before chasing all over the house. This happened earlier and she ended up back in the same room where she started after about 5 minutes or so, and actually looked surprised that the non-existent thing she was chasing has disappeared, before sniffing all over the place for it. Her sister just looks at her when she starts as if to say "here we go again...".

There no nip in the house (my cats have been taught to just say no), they don't go out so haven't come into contact with any toxins, and as far as I know they haven't fell off anything or launched themselves into the window recently (they tend to miscalculate their jumps into the window from the couch some times and bang their heads on the window). She's still the same as she is usually, although she's on heat at the moment (fun for me cos she's tarting up to me more or less constantly, even as I type this), but can this cause it. I think I heard something years ago that cats will actually hallucinate mice sometimes, although in her case it would probably be the mouse shape on their laser pointer, but never believed it.

Depends what they've been smoking.

Is she just having a mad 5 minutes? I found an older thread on it.
http://forums.digitalspy.co.uk/showthread.php?t=941402

No, it's different from them launching themselves around because she definitely appears to be focusing on something. Sphynx even wonders what she's seen because she'll look at the same point and look at her as if to say "I don't see it". I followed her around earlier when she did it and she's definitely chasing something she *thinks* is there.

My wife and I have both seen a 'ghost cat' (please don't laugh - my wife did until she saw it a few days after I mentioned it) before we had these two and I'm wondering if it's still here and she's seeing that. Mind you, cats are a lore unto themselves and most the time I haven't got a clue what Blaze thinks she is doing when she goes on her little escapades around the house.

I've noticed when I'm in the bedroom, my cats sometimes stare fixatedly at the door when it's closed with a wide-eyed look, as if something is standing there or is about to open and come in, even though I live on my own.

Perhaps they can see and hear things that we don't - who knows.

I know exactly what you mean (especially the buttwiggle).

Mine tend to "glaze-over", wide pupils, tail twitch, then - pounce! Run around time. Very amusing.

someone once told me they believe that when cats are doing that they are actually living in a future moment and to our eyes are acting out something that will happen.
They also felt that cats are more than a little bit phsycic.
She may have been a mad cat lady though....Cats certainly do seem tobe quite good at getting their own way though.... hmmmm....