Should I be worried?
Had a lovely warm bath, washed my hair, had a pedicure - and was sitting, quietly relaxing, with an episode of 'Morse' and a glass of red when - suddenly - both cats leapt out of their beds - ran to the sitting room door and sat there - all fluffed out, growling and staring at the door.
Went to look - there was nothing and nobody there - nor was there any sign of anyone outside.
They are still staring at the door - still fluffed out but not growling any longer.
It is most disconcerting!