Hi there is a new cat in the neighbourhood and he has been bullying one of my cats, yesterday both my cats were eating (Brother & Sister), when this new cat managed to get in without me seeing him and appear in the kitchen whilst both mine were eating, as you can imagine all hell broke loose, the new cat run out the house but both of my cats were fighting with each other. They are both now very wary of each other and as soon as one comes near the other, they are spitting at each other. They have both been brought up together, as I said they are brother & sister. Any advice as to what I can do. Thanks
Their behaviour is quite normal after getting a shock like this and they will return to their normal selves as soon as they settle down. They will be on edge for a few days but youdon't need to do anything, just make sure the big bully isn't able to get in again.
Lotty is quite right - they have been unsettled by the interloper, and they express their anxiety by falling out with each other. They won't remember it for long, and as they calm down, the aggression will subside naturally.
Just ignore them - don't try and separate them, or behave differntly, let them come around on their own - it's better for them, but a little distressing for you.