thanks everyone. Yes, I use the "time-out" system, but that doesn't help much when we're not home.

I'm watching them now for the next time that Strauss starts to stalk Sid because I want to try something that I read on another web site. It mentioned scruffing the instigator (grabbing him by the back of the neck), kind of pushing the head towards the floor, and hissing at him. Supposedly this is supposed to help mimic the kind of instruction that he would have received as a kitten.

ah, the joys of trying to understand what goes on in their little brains.

We are determined to find a solution though - no matter what, he won't wind up in a shelter.