I have a female 2 1/2 year old cat and is neutered etc. Shes perfectly healthy so all good but here is my problem with her. She is quite shy when around other people and will hide till they have gone. She does go out but is kept in at night. When ever another cat enters the garden she runs in and straight up at the window looking out. She does this even uf shes indoors to. Soon as she sees another cat out of the window she goes mad. Heckles go up and her tail all bushy and she spits and growls. So today she spots a cat out of the window as i was shutting the window and went a bit mad. She scratched my arm to bits as i was shutting the window as the other cat was on the fence. Shes fine with my other cat and shes very lovable and playful.
Is there anything i can do to calm her down when she spots a cat when shes at the window. Has her claws trimmed regularly to.