Welcoming a new kitten to your home is one of the most exciting things. I bet you’ve been counting down the days to bring your little bundle of fur into your family! However, if you already own a cat, it is common for them to be less fond of there being a new kitten in their home.
As such, it is normal for cats to hiss at new kittens. Cats are independent and solitary creatures and so the arrival of a new cat in their home can cause tempers to rise. This panics many owners who desperately want their cats to be friends. “When will my cat stop hissing at new kittens?” many owners ask frantically.
Thankfully, the initial tension between your two cats should calm down once they have settled into sharing their home and routine.
However, how you introduce your cats can drastically impact how your two kitties get along in the long run. First impressions are everything!
In this article, I share all the reasons why cats hiss at new kittens so you can understand how to help ease this conflict. I also run you through a step-by-step guide on how to introduce your new kitten into your home to help keep any tension and aggression between your two furry friends.
Why Do Cats Hiss at New Kittens?
It is common for cats to hiss at kittens or any new animal that invades their home.
Cats are independent creatures that love their routine and want things precisely their way. A new kitten can disrupt this and cause all kinds of tension!
Here is a closer look at the five most common causes of cat-on-cat conflict when bringing a new kitten home.
1. Their Routine is Disturbed
Cats love routine and thrive off having a set schedule each day. They will likely wake up at the same time each morning and have their meals at the same time throughout the day. If you have a scheduled playtime with your cat, they’ll also know when this is coming and when it is time to go to sleep in the evening.
What’s more, cats also get used to your routine. They learn to know when you’ll be awake and when you’ll be asleep. They get used to what hours of the day you spend at home and for which portion of it you’re at work. They become accustomed to where in your home you spend most of your time and know precisely when and where to find you.
When a new kitten comes along, both your and your cat’s routine can be disturbed. For one, they’ll probably be receiving far less attention from you than usual. Your movements around the home might be different, and even your sleeping pattern can change if your new kitten keeps you up at night.
This can make your old cat feel very unsettled. They will realize that it’s since this new cat has been in your home that these changes have come about. Therefore, they start to begrudge your new kitten and hiss to show their discontent. You must keep your cat’s routine and environment the same and try to show both cats equal amounts of affection to ease the transition and stop them hissing.
2. The New Kitten is in Their Territory
Cats are highly territorial creatures as well and spread their pheromones by rubbing and urinating to claim an area as “theirs”. Suddenly having a new kitten in their home will make them feel extremely on edge. They will be able to smell your kitten’s pheromones in your home and will feel as if their private and personal space is being taken away.
Territorial aggression is a real thing and can get pretty nasty. It is instinctive of the cat to hiss or even attack the person or animal that has invaded their space. I have had a cat biting and attacking me because of territorial aggression before, and it needs to be avoided where possible!
The best way to avoid this is to ensure your cat still has places and things that are “theirs”. For example, both cats should have their own litter box and food bowls. Even with measures like this, most cats will be reluctant to share the home at first and start hissing. However, within a week or so your cats will start to realize this new family member isn’t too bad and tensions will ease.
3. Your Cats are Incompatible
In most multi-cat households, there will always be one dominant cat and one subordinate cat. Either your new cat or your old cat can become the dominant feline. This is more dependent on their individual temperaments than who was their first.
However, issues can arise and a cat and a new kitten won’t get on well when they are too similar to one another. If both are vying to be the dominant cat, sparks can fly. This usually happens if you have two males or two females that are of a similar age and size.
On the converse, having cats that are complete opposites from each other can also cause your old cat to hiss and be resentful. For example, if you have an older cat that has lived its entire life by itself, a new energetic and playful kitten will be a lot for it to take. As such, it can be harder for these cats to see eye to eye. Always consider how compatible your cats will be before purchasing a new kitten.
4. Your Cat Feels Trapped
When a cat feels scared or threatened, it can either choose its fight or flight response. This means that they either run away from the stressful and frightening situation, or they prepare to fight and become territorial and aggressive towards whatever it is they fear.
For the reasons mentioned above, a new kitten entering your household is extremely stressful for cats. However, the situation is exacerbated if your old cat feels like they are trapped and cannot get away. They no longer have the choice between fight or flight – they instead are forced to face their fears and start hissing at your kitten.
Therefore, it is vital to never force your new cats to be together. There should always be an escape route so your cat knows it can simply walk away from the situation if it all gets too much. If your cats are in a room together, ensure you leave the door open and stay inside the room to supervise their interactions.
5. They Have an Aggressive Temperament
Some cats hiss at new kittens simply because they have an aggressive temperament. This is often the case with cats that have gone through trauma in their past or have been rescued. These cats are the more difficult to get to warm to a new kitten and this hissing and aggression may persist for longer.
If you know you have an aggressive cat, getting a new kitten may not be the best idea. As much as you want a new kitten, keeping both your cats happy is crucial. If you are insistent on it, you can try things like pheromone diffusers to help calm tensions. Your cats might not ever become best friends, but they may be able to live together amicably at a distance.
How to Introduce a New Kitten to Other Cats
Introducing two cats can be difficult without any form of hissing or tension. In most cases, the hissing will only persist for a few weeks. Cats will quickly adapt to their new normal and realize that their new roommate is in fact a friend. However, this does depend on how the cats are introduced to each other. Do it correctly and you’ll soon see the hissing stop.
If you’re unsure about how to introduce two cats, here is my step-by-step guide. I have used this method multiple times throughout my life and can confirm it is the best way to help your new kitties become best friends.
Keep Your Cats Separate at First
The sudden addition of a new cat to your home can be overwhelming. Therefore, you should keep your two cats separate at first to help ease tension. Besides, your new kitten needs to get used to their new home gradually otherwise they may become stressed as well, making the situation worse. Knowing where kittens should sleep at night and setting up an appropriate area just for them can go a long way in perfecting a seamless introduction.
Create Positive Associations
While keeping your two cats separate, you’ll want them to see each other in positive situations. This helps them to associate the other with positive things. For example, try feeding your cats at separate sides of a door. You can also swap their bedding over every couple of days to help your old cat slowly get accustomed to the new pheromones in their home.
Let Your Cats Explore Freely
If there has been no hissing or other aggressive behavior towards your new kitten for several days, you can slowly allow the two to properly meet. When doing so, be sure to let your cats move freely around your home. As mentioned, feeling trapped in a threatening situation can make the conflict worse. You should still expect some hissing at this stage, so always monitor their interactions. If they continue to hiss for more than 2 minutes or show signs of attacking each other, separate your cats again.
Gradually Increase Time Spent Together
Once your cat and kitten can explore freely without hissing, you can gradually increase the time they spend together. Still supervise your cats at this point until they can happily spend several hours together without showing any signs of threatening behavior. Once there is no hissing for around a week, you can then allow your cats to explore without your supervision.
Provide Multiple Resources
While this is all happening, you must provide multiple resources for both of your cats. For example, you’ll need to look into litter box ideas for multiple cats and ensure they both have their own private space to do their business. Again, giving your old cat and new kitten their own bowls can avoid food-related conflict. A feeding station will a collar sensor stopped my cat from bullying my other cat at mealtimes, but see what works for you! Giving each of your cats their own bed and toys is another worthwhile investment.
When following these steps, the entire process should take no more than two or three weeks. During this time, your two felines will become more accustomed to each other and learn to share their space and resources. Therefore, as a generalization, the answer to “When will my cat stop hissing at new kittens?” is around three weeks tops.
However, this does depend on your cats as no two kitties are the same! Sometimes the process will take longer, especially if you have an older cat that is accustomed to living alone or a rescue cat that is naturally more aggressive. In these cases, go through steps 3 and 4 extremely slowly. If tensions do start to rise, clap your hands to cause the conflict to diffuse before putting your cats in separate rooms again.
MY FINAL THOUGHTS
So, when will my cat stop hissing at new kittens? Well, this will only happen once your two cats feel comfortable living in your home together. They need to get accustomed to their new routine and new family member. Once they have done so, the two should get on and could even become best friends.
In most cases, this process will take around 2-3 weeks. However, some cats might immediately get along well from the get-go, whereas others will be more reluctant to accept the kitten into their home. Go at whatever pace they need and never try to rush anything. With the appropriate measures, a little patience, and some effort on your part, there is no reason why your two cats can’t get along.
I’ve read that it could take 8-12 months, not ‘three weeks tops.’
It definitely can take that long. It could take 3 weeks, it could take 2 years, or they could never get along. It really depends on the cats and all kinds of variables. But IDEALLY, under the best circumstances, it’s not uncommon for things to settle down in 3 weeks.
I have two cats. One was about a year and some months when we found the 3 month old. The little one quickly dominated the older cat but they got along. She just likes to get zoomies and chase the other one, while the other one hisses as she’s not in the mood. But then a few hours later will take her revenge by slapping her and chasing her instead.
The older one is all for making friends and seeing other felines, she regularly begs to go outside and explore with her street friends. The younger one is Alpha and doesn’t want anything on her territory, and easily gets stuck somewhere outside, so we don’t let her out. But we noticed if other cats come to the balcony and she’s around, she’ll hiss at them from inside.
We recently found a malnourished kitten and brought it hope to recuperate it. The older one has taken a keen interest and wants to come and sniff her and see if she could be her new friend. The younger cat, the Alpha, is hissy around her and I’m worried it’s just not going to work. But I’m hoping with time she can realize that this cat will not replace her, but be another friend to play with.