Re: Longest Running Thread EVER
Well, before going to psychotropics, I'd go with one of the flower essenses.
Feliway is usually used to calm cats and get them more used to an area. Often used in carriers before we transport, and also to get cats to not mark. Though my experience is that it seems to have effect on 50% of cats.
For a lot of behaviors, I've found some of the products from Bottled Blessings to be of use. From them, my wife and I use "No Bully" mainly for our thug of a cat. When we don't use it, his torment of the other cats increases.
I think they have a version for getting cats to like each other more, though maybe just a calming one.
However, Havoc may just not want to deal with another cat. And not much will change that. Heck, out of my seven, three of them like each other, two are in seperate areas because they don't like other cats. One's the computer room cat, the other is the TV cat. The others figure out places on the bed at night.