Until 13th May 2003 I owned 2 cats, a 7 year old castrated male and an 8 month old spayed female. On May 13th I acquired another older castrated male. He is very friendly and not at all aggressive. He just wants to be friends with my 2 original cats. They wont have any of it.There have been no fights,just lots of hissing and growling.Can anyone suggest anything I can do to help the three of them get along together? The new arrival does not go out yet,(he came from a couple a few doors away and we are worried he will keep going back to them),but the original 2 cats spend a lot of time outside,but sleeping indoors at night.