We have a 2 year old lovely, wussy cat. We got her as a rescue when she was 12 weeks old, and she has been spayed. She is mostly indoor although she does sometimes come into our back garden for a quick look around if we are out there.
A very large cat has started visiting us at night. He comes up to the window and stares at our cat. She gets extremely wound up by this and obviously finds it really distressing. He goes around the whole house (we're a detached bungalow with a few floor to ceiling windows so he has easy access) and goes up to each window to stare at her. She follows him from window to window and howls, grunts, and generally gets very upset. I think she's trying to warn him off but he stands his ground.
Ever since this has been happening our girl has started peeing outside of the litter tray (mostly in our clean and dirty laundry) which she has never done before. She also seems generally unsettled and stressed. When the sun starts setting she goes to window and waits for him, and gets very wound up. I think she sometimes stays up all night, when she used to come to bed and sleep with us from about 1am. She has also become a bit aggressive with my daughter, when she used to be very gentle. She is clearly very affected by this other cat's visits.
I have seen this cat a few times during the day - not in our garden but hanging around the road or in neighbour's gardens. He doesn't have a collar but is very clean and friendly with people so I think he is someone's pet.
What do I do? My poor cat seems to really be suffering and all the solutions I have read about online seem to be designed for people who don't have cats - sonic alarms, dog pee spray etc - I don't want to do anything that will upset my cat more.
Please help!