Many cat owners are motivated to introduce a new kitten to the household by the thought that their existing cat will appreciate having a new companion. In my experience, this is often true – at least in the long run – but the initial introduction period is not always plain sailing. Indeed, people are sometimes surprised to find that their cat is less receptive to the new addition than they expected. Often, this manifests in the cat hissing at the new kitten.
Why Does My Cat Hiss at My New Kitten? The hissing sound is a display of territorial aggression, warning the new kitten and establishing their position in the household hierarchy.
While the behaviour is extremely common and can be considered normal, it can be stressful to manage and is not conducive to a peaceful household. Fortunately, there are steps that can be taken to mitigate against the problem, settle your cat down, help your cat and a new kitten to socialise with one another in a calmer way, and ultimately help the two cats to become companions that happily co-exist within the same space.
Why Cats Hiss At Each Other
If you are a cat owner and decide to introduce a new kitten to your household, you are almost certainly hoping your cat will take to the change well and that the two will become friends. Unfortunately, in a great many cases, the initial introduction is less peaceful than this, with the older cat displaying signs of aggression towards the young kitten. By far the most common form of aggressive display is hissing and/or spitting.
The hiss itself is created by the cat arching its tongue and expelling air quickly. This is usually accompanied by lips being pulled back to display the cat’s teeth, and your cat may also arch its back. It has been hypothesised that the hiss is intended to replicate the sounds made by natural predators in the wild, including snakes.
This can come as something of a shock, especially if your cat is usually calm and affectionate. However, it is important to understand that the hissing behaviour itself is extremely common and normal. In other words, you do not need to take it as a sign that your cat has a bad personality, is anti-social, or is overly aggressive.
For the most part, cats hiss as a way to warn other animals to back off. Most cats are territorial by nature and your cat will almost certainly see your home as its territory to defend. Overall, this is a good thing, because it means your cat feels settled in your house. The downside is that your cat is likely to feel an instinctive need to protect their territory from intruders and outsiders – including your new kitten!
Hissing can be interpreted as a sign that your cat feels threatened or scared, but it also functions as a warning that it is willing to act aggressively, as a proactive form of defence. While it is not necessarily an indication that your cat is about to attack, it should be interpreted as an aggressive warning and an attack is a possibility.
Aside from that, however, hissing also has another key function in helping a cat to establish its position in a social hierarchy. One of the reasons your cat may hiss at your new kitten is to cement its place as the elder and more dominant cat. This can actually help to teach your kitten to respect the older cat’s boundaries, and once your older cat feels secure in knowing the kitten understands its place, the hissing is likely to stop.
Should Humans Interfere?
At this stage, you may be asking: should I interfere with behaviour that is a natural part of feline behaviour? It is a perfectly valid question and the idea that humans should leave cats to it is not entirely without merit. In fact, most experts would agree that the hissing should not be punished, and there is some truth to the idea that allowing your cat to hiss at your kitten will help them to establish a functional hierarchy more quickly.
Yet, at the same time, many aspects of caring for a cat involve interfering with what it would naturally do and it is important to prioritise the safety of your new kitten. Although hissing itself is natural and harmless, it can be a precursor to your cat attacking your new kitten, which is why it is essential to be vigilant.
While the hissing is still occurring, it is imperative that you do not leave your cat and new kitten alone in the same room, unsupervised, because this could put the kitten in physical danger. It is also crucial that you are ready to step in before your cat makes any genuine attempts to attack your kitten. If you are out of the house, or otherwise unable to attend to the cats, they should be kept separate and the cat should not be able to gain access to the kitten.
Allowing a certain amount of hissing can be useful in helping the cat to establish its place in the household hierarchy. For this reason, as long as the behaviour does not progress beyond hissing, your cat should not be penalised for demonstrating natural behaviour. It is also unlikely to associate the punishment with the hissing. With that being said, there is a balancing act, as hissing should also not be actively encouraged or rewarded either.
Steps to Minimise the Problem
So far, I have covered the reasons why your cat might hiss at your new kitten. However, most likely, you are also seeking some advice to help resolve the issue. The good news is, there are some simple steps you can follow to minimise the conflict and ensure the two cats eventually settle and become peaceful companions.
One of the best things you can do in the early stages is established a safe room for the new kitten. This room should be secure, so the older cat cannot access it, allowing the cats to be separated when necessary. A baby gate can be an ideal solution for keeping the cats separate, because it protects the kitten, while simultaneously allowing the cat to see and smell the kitten, and get used to its presence within the household.
A carrier can also be an invaluable tool, allowing your cat to become familiar with your new kitten while keeping them apart. Again, as with the baby gate idea, this allows both cats to see each other and pick up on each other’s scent. It also ensures the kitten does not accidentally impose upon the cat’s boundaries too early.
Over time, you should allow the cat and the kitten to spend more time together. They should always be supervised and you should be ready to step in if the cat becomes too aggressive, or if there are other unwanted behaviours.
It is important that you continue to provide the older cat with plenty of attention and affection during the initial settling in phase, so that jealousy does not develop. After around a week of taking these steps, your cat and kitten should be able to spend longer periods of time together. Once they have become comfortable with one another, and the hissing and other signs of aggression have ceased, you can start to think about leaving them together regularly.
Other Behaviours to Be Aware Of
As previously stated, cat hissing is sometimes accompanied by spitting and this should not be viewed as being any more aggressive than when hissing occurs without spitting. Both behaviours are part of the same core instinct to display territorial aggression, to warn off other animals, and assert hierarchical dominance.
In addition to this hissing and spitting, there are some other behaviours that are common when introducing a cat to a new kitten and it is worth having a basic understanding of these too, so that you can respond appropriately. The most common is for your cat to attempt to swat at the kitten with its paws. This is unlikely to cause any major harm to your kitten and is mostly another warning technique, but you may need to intervene if it becomes too aggressive.
Should your cat add to its hissing with either a shrieking or growling sound, this is a sign that the cat is preparing to escalate its aggression further. You should take this as your cue to get involved and separate the cats before the older cat is able to cause any physical harm to the younger kitten. Gradually, over time, the more the older cat is exposed to the younger kitten, the less aggressive and territorial it will be.
Occasionally, rather than displaying traits associated with territorial aggression, your cat may instead become anxious or depressed by the presence of your new kitten. This is generally because cats are naturally averse to change and it stresses them out. Depression and anxiety can manifest in a number of ways, but examples include reclusive behaviour and a loss of appetite. Fortunately, this will usually improve gradually over time.