Weirdly, over the past few weeks, we have been experiencing the very distinct sound of what appears to be a cats collar bell tinkling- exactly like a cat rapidly shaking its head like they do. It puts our cat, who is very timid, on the alert and she begins pacing up and down, apparently recognizing the sound. No other cat noises heard and since the house is tiny there is no possibility of another cat sneaking in unseen. No TV or radio on at the time and no possibility of a cat accessing the sub floor area. At first I thought it may be the sound of a zip or something clattering about in the washing machine or dryer but it happens when neither of these are switched on. We don't have any wind chimes or anything which would make that sound. Funnily enough the sound brings a grin to my face for some reason. 2 cats have died in the house in the past couple of years but I am looking for a none esoteric explanation. Anyone had a similar experience or a possible explanation?