I've got a slightly nervy cat, who has on several occasions when I've been away toileted in just the one room - my office. I thought it was because other cats might be accessing the house, but that stopped early in the spring when I got the microchipped catflap working. That was also when my other cat, who she didn't like, died - so she's been the only cat ever since, so no stress in that respect. Last time I was on holiday (in the summer) I kept the door of that room closed and there were no surprises in any other room in the house. I've also cleaned the rug with an enzyme spray and taken down the (pissed upon) curtains. I also have a litter tray just outside the room, which she never uses. But then at some point last night she did a pee on the rug in the office, and I have no idea why. It was very windy outside but then it often is. Apart from always remembering to close the door of the room when I'm not in it, what else can I do??