Beware of cat

Mr.Bonkers is a watch cat. When the doorbell rings, he is right there to
hiss, scratch, bite any stranger that comes into the house. He defends his
property with a vigor. Every other cat I have ever know has prefered to run
and hide when a stranger approaches. Not this guy. Lord help any kid that
ever chases him.

When we have a visitor sleep overnight, Mr.Bonkers sits in a chair all night
long and stares at them. Its rather upsetting.

IS there any way to teach a cat to be less agressive? He is an indoor,
neutered cat with access to a screened in outside room. HE gets along well
with the other cats in the neighborhood that roam free (thru the screen that
is) .It's just he has an active dislike for other humans.

With his human family he's a perfect gentleman. He never raises a claw or
bites (for blood). He's a perfect kitty except for this reaction to
strangers.