Two weeks ago we brought two cats home from the animal shelter. This one is 9 months old and the other we were told was 22 months, although we think he's younger because he acts like such a kid. Our resident cat is, of course, less than pleased. Though when she thinks I'm not looking, she looks calm and interested. So far we've avoided any knock down, drag out fights, but there's considerable growling and an occassional brief chase by our resident cat. Behaviour which is largely ignored by the two young ones! Luckily the two new ones are pretty companionable. I guess they had to learn to get along at the shelter.