Yes - I'm having territorial problems over here too - the neighbor's daughter moved back home with 3 cats - she just started letting her male outside to be allowed more 'freedom'... My cats are strictly indoor kitties - Oh I do let them out occasionally with their harnesses on so they can munch on the grass.

But now this boy is hanging out and mine just go balistic. He'll come up to the front door screen and then we have fights thru the screen, then with the cats all upset they go after eachother. Then its 'time-out' time and I separate them for a few minutes..... My momma kitty is just nervous all the time now - I guess she's in protection mode.

I'm tempted to let one of mine out to see if they won't give the boy an attitude adjustment but the only real option is to let the 11 year old out to teach the lesson and she is somewhat handicapped by an earlier accident she had though she can probably still get the job done. The younger 2 year old hasn't got any upper canines do she can't do any damage by biting nor does she have the rabies, FIP or feline leukemia shots as she is an indoor kitty and no need for those things. And the baby is just 3 months old and would probably get eaten...

I'm not sure what to do short of fencing in the house/yard...

Canie