I've just adopted a third cat and we're a week in to the settling in process, just seeking opinions on whether I'm going about it the right way and open to any further tips! Did lots of reading around beforehand but there's a lot of contradictory info out there, this is my first experience of adult cat introductions. Apologies it's a bit of an essay...
Background: I had two rescue boys who are approx six years old and I've had them for five years. Both are inclined to be shy and fearful with other people, but are lovebugs with me. One is pretty bossy and dominant in temperament in the household, the other is more retiring. The quieter one I've seen interacting with neighbour cats in a chill way, the bossy one sometimes chases them out of the garden. Both spend a lot of time outside by choice, they tend to pop in and out several times in the evening for dinner and are shut in overnight.
New cat: is a 3.5 year old rescue boy, he's had a previous family but they got a dog and he really didn't approve so moved himself out and ended up with a rescue. He's a very friendly and sociable little chap, straight away he was eager for attention and stroking and play. His foster mum said he'd previously tried to get an older cat in a neighbouring pen to play with him and she thinks he'll get on well in a house with other cats. We started him off shut in the spare room and resident cats were pretty oblivious, even when he meowed or was jumping around in there. He settled in to that room very quickly so after couple of days started to let him explore the rest of the house while the resident cats were outside. Dualscan cat flap is letting resident cats come and go while he is indoors only for now. He goes back to sleep in his base room by choice if I'm not in the house.
Meeting: the first time resident cats came in and new cat was downstairs, I kept the kitchen door shut and gave them some treats on the other side. Gradually cracked it open a little and continued offering treats. This progressed across a few meetings to the door being opened more, both parties being given treats. They then started being given treats in the same room. While they're actively eating chicken everyone is fine, when distracting food stops and they start scoping each other out it gets a bit more iffy. Across the initial meetings my more chill resident cat was quite bold with him, and was doing a lot of staring and moving in to his personal space. New cat was very excited, wasn't hiding at all - he'd creep right up to observe from the bottom of the stairs or around the side of a chair. He made eager chirping noises. Less chill cat was less enthusiastic and mostly ignored him, gave a few little hisses when he approached. Thought was going pretty okay.
Further meetings: we've had a couple of times where more chill cat has gone upstairs and new cat follows him, and sits across a stair so he can't get back down. Left to own devices, when resident cat tries to creep down the little gap new cat has swiped at him. New cat also once chased up to crowd him at the cat flap, resident cat was hissing and growling in warning but new cat didn't back down till I intervened to shoo him away. Less chill cat has had a few meetings where he's given warning hisses across the room and new cat has pretty much ignored him and still made attempts to sneak up on him. Once he also crowded him at the cat flap and resident cat went into full defensive yowling mode, new cat again wasn't very deterred.
New cat is often chirping while he does his "stalking", his tail isn't puffed up but sometimes he'll have his ears back. The classic is one of the resident cats comes in the cat flap and new cat will leap up and rush to observe from around the side of a chair or another spot a few feet away from the food bowls. He'll stare intently while resident cat eats, then as they turn to walk back to the cat flap he'll rush up behind them. If he's distracted with treats or I lure him into playing with a toy, the other cats pretty much ignore him. They don't respond with puffed up tails or anything and are happy to eat food and be stroked or brushed while in the same room as him. New cat is shut away in the spare room overnight until after the resident cats have breakfast and are let out in the morning.
I feel this isn't too bad for just over a week in. The resident cats aren't thrilled and have had some conflict, but don't seem about to leave home! When they have the place to themselves they behave just the same as before. But I'd like to reduce the angry reactions - which I feel are down to the new cat pushing boundaries, to be expected, but also just finding the other cats far too exciting when they appear. They're fine if he's still and quiet, but creeping up to them while they're eating or rushing up while they're at the cat flap is intimidating so of course they react with fear. This is why I'm trying to distract him with toys so he won't try to stalk and chase them. But longer term they need to be okay to be unsupervised, and I don't want him rushing up to the cat flap whenever they try to come in. Anything else I can be doing to help with this settling in? We've got feliway and feliway friends on, I try to give him lots of playtime with wand toys and all sorts especially in the evening, and give him treats when he's calm and quiet. Open to all tips and thanks for reading!