Friday, 25 September 2015

Behaviour focus: introducing cats

In this week’s behaviour focus post, Cats Protection Behaviour Manager Nicky Trevorrow explains why two cats may not get along and how to gradually introduce them to one another.

I’ve got a new cat. I introduced them to my other cat really slowly but they still don’t get on. What can I do? 

Congratulations on your new cat! During the excitement of having a new cat, it can be very tempting to power through the introduction process, and this is the biggest reason that Cats Protection has cats returned to the charity – as they didn’t get on well with the resident cat and vice versa.

So what can be done for two cats that aren’t getting along? It varies between situations and the individuals involved. Firstly, are both cats healthy? If either cat has an underlying medical condition, this needs to be addressed first. If the new cat is still quite new to the house and the intensity of the tension is quite low, then it may be best to re-introduce the cats to each other. Some may just need to go back a step; others need to go back to the beginning.

Every cat will vary but adjusting to new surroundings can take at least a week, so they should have no contact with the resident cat at all in that time, as well as during the scent swapping phase (see below).


When adding a new cat to a household that has other cats, it’s worth bearing in mind that they are naturally solitary creatures and do not require the companionship of other cats. They can also be very territorial which means that careful considerations need to be made when introducing a new cat. However, if there is no competition for food or sleeping places, cats will usually tolerate each other and some can become good friends. It will take patience and understanding, and always work at the cats’ pace.

Cats sleeping intertwined
Intertwined sleeping can be a sign of cats in the same social group; photo by Jackie May

Important resources for cats

Step 1: If you have an existing resident cat, ensure that all his routines remain the same where possible. Place the new cat into a room that the resident cat uses the least.

In each space, provide each cat with the following essential resources:

  • food and water (cats like to drink away from where they eat, so place the food and water bowls in separate areas)
  • somewhere to hide (it is very important for cats to have somewhere to hide particularly while they are adapting to a new environment, such as a cardboard box on its side or under the bed)
  • somewhere to get up high to view surrounds in safety (on top of a wardrobe, shelves, window sills, stools)
  • somewhere to sleep (igloo beds, cardboard box, blankets in elevated places)
  • toys (be aware that the cats may not want to play while they are settling in)
  • a scratch post (try placing near to where the cat sleeps as cats often like to stretch and scratch after they wake up)
  • litter tray (place this away from food and water)

You can install a pheromone diffuser, such as Feliway, to make the environment more reassuring for the cats. Feliway is a synthetic pheromone diffuser that reproduces certain reassuring properties of cats’ facial pheromones, which convey a message of wellbeing and a feeling of security. It mimics the scent left behind when a cat rubs its face against furniture or its owner’s legs. Plug the diffuser in about a week before your new cat arrives and leave it on all the time until it runs out. It is worthwhile having one diffuser in the room the new cat will be in and one in the area of the house that the other cats will be in.

Introducing cats to cats    

Step 2: Before introducing the cats physically, mix and spread their scents by stroking each cat with a separate soft cloth and leaving the cloth in the other cat’s environment to sniff when the cat is ready to investigate.

Step 3: Keep swapping scents until the cats are showing no reaction to the smell and both cats have settled in. Then you can progress to allowing them to see each other, but not touch or meet one another. Try placing a glass or mesh door between the cats, and allow each cat to approach or hide as they choose. Do not progress to a face-to-face introduction until the cats either ignore each other or show positive feline social behaviour (such as blinking at each other, tail up greeting behaviour, attempting to rub heads on each other through the barrier and sleeping near each other by the barrier).

Littermate kittens
Cats are more likely to get along if they are related, such as litter mates, although this is not a guarantee; photo by Martin Dewhurst
Step 4: When your cat has settled in (which can take some cats weeks) make introductions at feeding time; cats form social bonds best around this time. It helps to:

  • ensure easy escape routes are available for both cats
  • start in a fairly large room where they can choose to stay at a distance from each other
  • supervise the cats when they are together
  • work at a pace that the cats are comfortable with and go back a step if necessary
  • only introduce for short periods of time 
  • gradually start to fuss or play with the cats for a short time, so their attention is on you, before putting the food down
  • if this is tolerated, then gradually increase the time they spend together

It can take anything from a day to many weeks for cats to tolerate each other. Do not chase or shout at the cats as this will only lead to them associating each other with bad things.

Step 5: As they become more comfortable in each other’s company, try giving them tit-bits to encourage them to come closer. Finally, try feeding them in the same room with their bowls far apart. Over time you can move the bowls closer together. However, do not aim to feed the cats next to each other; lowering their head to eat or drink can make a cat feel vulnerable, so place food and water bowls slightly away from the wall, so the cat has space to sit with its back to the wall and the bowl in front of them, so that they can survey the room while eating or drinking.

Step 6: Once both cats are relaxed while feeding, start including short periods of time where the cats are not distracted by playing or fussing. Supervised time spent together can be extended. The aim is for the cats to associate each other with pleasant happenings.


  1. Good article. I am not sure whether this question can be answered, but I have just rescued 3 girls, all mothers who weaned 22 kittens between them. They are Lucy (2.5), Cindy (2) and Lottie (18 months) They were recently brought home and "met" my resident cat Frankie (4). Cindy and Lottie were not bothered by him but Lucy hated him on contact which was fine. I went through much of the items you detailed above by way of getting them used to each other but even after 3 months, if Lucy sees Frankie she corners him and attacks. Frankie is terrified. We think Lucy is protecting her daughter and Lottie from an intruder, but its only Lucy who is the problem. Frankie now spends much of his time outside and only comes in at food times and at bedtime where he sleeps with us. We have had to chop the house in two: Frankie resides upstairs and the girls downstairs. We would like things to return to normal soon but how can we go about doing this?

    1. Hi Angie, it sounds like you may need to re-start a slow introduction programme. Keep the cats separate for the time being and start the scent swapping stage again. You’ll need to get a clean cloth and rub it on their cheeks where the scent glands are and then leave the cloth in the middle of the floor with the other cats to investigate.

      If Frankie lives upstairs and the rest live downstairs, ensure Frankie has all the resources he needs upstairs: litter trays, food bowls, water bowls, hiding places etc. In an ideal world, one resource per cat plus one extra gives the cats choice. It will reduce any competition between the cats as well as reduce the stress of one cat coming downstairs through another cat’s territory in order to access food.

      Also ensure that all cats are healthy as stress can manifest itself in lots of different medical conditions. For more information, read Cats Protection’s leaflet Cats living together

      As this has been going on for three months already, it may be best to get a qualified behaviourist in to meet your cats and advise. We'd recommend a referral to a member of the Association of Pet Behaviour Counsellors (APBC)

  2. Thank you for the interesting article. Regarding your point regarding litter mates being more likely to get along, does gender make a difference? Are twin sisters, twin brothers or twins of each gender more likely to be compatible?

    1. Hi Caroline, generally the sex of the cat doesn't affect whether they will get along or not. It depends more on their socialisation as young kittens (eg whether they had friendly encounters with other cats or even the scent of another cat), personality, previous experience and if they have any medical conditions affecting their tolerance of other cats. Hope this helps.

    2. Thanks for the prompt and helpful response. Interesting; as you say, I suspect personality, as with humans, plays a huge part - domestic relationships are never simple!

  3. Hi there,
    We introduced a rescue kitten (George) to our house over 2 months ago and it has been a bit up and down. Our resident cat Darc, who we rescued over 2 years ago, has struggled to adapt. Initially she was quite aggressive with him, although usually more bluster than real violence! However the tables have turned now and George seems to attack/bother her, although because her is still under 6 months old this is not such an issue currently. We have tried Feliway, but this does not seem to have made a difference! They do not fight all the time and there are times when they are in the same room, usually when they are asleep or eating! We feed them at the same time to try and encourage bonding and we also spend time with them both. We have also tried to introduce toys that they can play with together, but George seems more keen. I'm just a bit worried about Darcy feeling ousted and George dominating more and more as he grows. Any advice would be greatly received. Maggie

    1. Hi Maggie, it sounds like you need to start again with the scent swapping stage. Have a read of our leaflets Welcome home and Cats living together

      As the cats become more comfortable in each other’s company and you’re feeding them in the same room, ensure they can both escape easily – placing an object such as a chair between the feeding bowls may help them feel less threatened. Over time you can move the bowls closer together but do not place them side by side. Cats can feel vulnerable when they are eating, so place food and water bowls slightly away from the wall, so each cat has space to sit with its back to the wall and is able to survey the room while eating or drinking.

      Ensure there are plenty of feline resources around the house: litter trays, food bowls, water bowls, hiding places etc. In an ideal world, one resource per cat plus one extra gives the cats choice. It will reduce any competition between the cats as well as reduce the stress of one cat having to walk through another cat’s territory in order to access food.

      If you're still struggling to keep the peace, then we'd recommend a referral to a member of the Association of Pet Behaviour Counsellors (APBC)

  4. Hi, About 6 weeks ago I adopted (what I was told) a sweet young cat, all was fine for a week, then she got flu and since she recovered from that she has turned into a monster, she will attack my arms or legs whenever she gets the opportunity. She will literally pick up the skin and try to shake it like live prey. I am trying to feed her by hand so she sees my hands as something nice but it is not working, what more can I do, when she is asleep she is so adorable but awake I am fearful of sitting down as I don't want to be mauled

    1. Hello, we’re sorry to hear about this. It’s really important that if you notice any change in your cat’s behaviour, you get her checked by a vet to ensure there are no underlying medical causes. Cats are very good at hiding pain.
      Please have a read of this article about aggression, taken from The Cat magazine: and also this blog post where Nicky answers some questions about aggressive cats

  5. we getting a female kitten in two weeks time and we already have a 6 year old male cat will this be the same procedures introducing them together or will it be different because its a kitten?

    1. Hello, the process to introduce them will be the same, however there are some additional things you may need to consider - ie it is best not to leave a kitten alone until they have settled into their new home. For more info see our leaflets and

  6. Hi, I found your website and articles very helpful. 5 weeks ago we brought home kittens who are currently 13 weeks . We already lived with couple of 14 year old moggies, brother (one very friendly, another one friendly but not very sociable and rather careful about anything new). Old boys are used to.going outside anytime of the day, and we also free feed them dry food and they get wet couple times a day. Kittens were introduced to then in stages, however we have made some mistakes: the day we brought them in we let both resident cats to sniff then in the cart carriers, both were not very impressed and left the room. We decided to keep kittens separate, so they live in our lounge (your top was to put them in the last used room, but we don't have one - is a large one bed flat). Kittens are growing well and never got scared or run away from the boys, they are very interested in the resident cats and would propably follow them anywhere.The more outgoing of resident cats got to the level of accepting the presence of young ones but is yet to achieve (if we've level of full relaxation around them). Kittens are still separated,but in ovations we let them to run around entire flat, same with resident cats. The outgoing cay makes it to the lounge and pays with kittens toys, indulged is catnip and even day on our lap there once. The other cat is very scared of them, or just does not tolerate them. He comes home only to feed and disappears straight street feeding. Every other night he will sleep with us in a bed. He smells of mulched leaves so I think he going a compost heap which keeps him warm. He did not lose weight and looks healthy.He can tolerate kittens only when they are calm and don't try to follow him or are running around. I would like to aid this situation so that he can feel safe and comfortable at hope and fell he can use entire house. Any advice?

    1. Hello - If you do not have a separate room for the new cat, you might try providing wall shelves. If you place the shelves as if they are steps up the wall and across, the shelves can let the cats avoid one another. One cat can escape up the "high" path that way. If you google "cat shelves" you will see what I mean. The cats need to be able to avoid one another.

  7. Hi. Hope you can help. I got a cat who is approximately 2-3 years old in February 2016 and I recently got a kitten. I have tried doing quite a lot of the things above but the older cat is making no real signs of improving at all. She's still hissing and snarling, she took a swipe at the kitten yesterday. Thankfully I don't let them get near enough eachother but it's getting very difficult. I am keeping them separate. I really don't know what else to do. A few people have told me to let them get on with it but I don't like the idea of that as I worry they may injure one or eachother. Is there anything else I can perhaps try at all? My house isn't huge really and my older cat is happy to just hide away upstairs and not come near the kitten who sadly I am having to keep in one room for his own safety. Please help!!

    1. Hello, sorry to hear that your cats aren’t getting along. Have you taken your older cat to the vet to rule out any medical reasons for the change in behaviour? Cats are very clever at hiding pain so a full check-up is the first thing we’d advise.
      If the vet thinks it is behavioural, then there could be a number of causes and a referral to a qualified behaviourist would be a good way to get to the bottom of it. You can search for one via the Association of Pet Behaviour Counsellors. Unfortunately leaving them to sort it out themselves won’t resolve the problem and could actually make it worse.
      If you’ve tried re-introducing them and following all the steps really gradually, and that hasn’t made a difference, it could be that your cats are not in the same social group. Have a read of our blog post at (copy and paste that address into your browser) and you’ll find some tips for helping to avoid conflict in the household.

  8. We took in an 11year old female 5 weeks ago. She initially had a few health problems but those are resolved now and she is healthy and settled into the house and used to us. She is still in the spare room though, as she is aggressive towards our 2 resident boys.
    They are currently rotating in and out of the spare room every few hours.
    She is used to their scent but still hisses and tries to attack whenever she sees them through a barrier.
    We have a mesh barrier with a blanket over it. The smallest and most laid back of the boys is being introduced first, by feeding them either side of this barrier (4 times a day). They started about six feet away from the barrier and have gradually got closer over the last couple of weeks. They are now eating happily about two feet away.
    However, if she catches a glimpse of him, she immediately tries to attack through the barrier.
    Will she ever accept another cat or will we have to find her another home?

    1. Ensure the female cat is neutered and all medical problems are completely resolved, as underlying medical issues can affect behaviour. If you were carrying out the scent swapping while she was undergoing treatment for her medical conditions then you may want to take a step back and re-introduce the scent swapping. Illness and trips to the vet can affect the scent profile of the cat and thus impact on the scent swapping process.

      During the daily scent swapping process (of a least about a week) the cats should not have physical or visual access to each other. Additionally, they should not be coming into the same space as each other even when the cat isn’t there. Scent swapping needs to be done with both resident cats in the house and the new addition. If you have any concerns about how the scent-swapping part of the introduction process was carried out, I would go back and re-do it as it can be the most integral part of the introduction process. See for more info. What you have been doing with the mesh barrier is good but you may just need to try and re-establish a more solid foundation.

      Aside from that, you can use the Feliway Friends Pheromone Diffuser to try and help aid the relationship but this is a support, not a ‘cure-all’. The pheromone diffusers should be left switched on 24/7. Switching on and off can reduce efficiency.

      Cats are inherently solitary animals so there is a strong possibility that she may not accept the other cats and in this case it would be better to rehome. Not being directly involved in the case it is difficult to say but you would want to set yourself a time frame to monitor for success. Either carry on trying what you are trying for another week (approx.) or go back and re-do the scent swapping stage and give yourself about three weeks (approx.). We can’t make cats like other cats, the best we can do is set up the environment so it provides the best chance of success. What you want to avoid is the middle-ground where the new cat simply learns to tolerate the resident cats as this can cause stress which is detrimental to welfare. This middle-ground scenario always ends up compromising the welfare of at least one of the cats in the scenario if not more. We hope this helps! For more info visit,

  9. Thanks very much for your helpful reply. Really useful advice.
    I think we will keep trying as long as she keeps making progress. If we get to a point where things are not improving, then we'll have to find her a home that she won't have to share.