Are you wondering why cats hiss at new kittens?

You might if you’ve just brought a new kitten home and your mellow cat suddenly turns into a hissing machine.

Well, you’re lucky because today we’re going to unravel the mystery behind this cat behavior.

Read on to find the answer!

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Have you ever wondered why cats hiss at new kittens? We're unraveling the mystery behind this odd cat behavior. Check it out!

Why do cats hiss at new kittens?

Cats do not like change. Not at all.

For example, my neighbors had a kitten that started coming to my house.

My neighbor was not happy about it, but the little one was very stubborn and practically invited itself into my home.

I named her Tabby, for obvious reasons, and we agreed to co-own her.

Ronnie was not happy about Tabby and kept her distance as much as possible.

However, whenever they crossed paths by chance, Ronnie would start hissing at the small kitten.

Do you want to why?

Keep reading to find out.

Related: Do Cats Like Being Picked Up?

#1 “Stay away! I mean it!”

Zuki's hiss

Can you guess which predators most animals fear in the wild? Snakes.

And do you know what snakes do? They hiss.

So, experts think that when cats have learned to mimic the sound of a hissing snake when they feel threatened.

When the cat hisses, she doesn’t want to get into a physical fight. If she wants a battle, you’ll know it.

She will be making angry, challenging sounds and puffing up her tail and body to look bigger.

So, your cat is saying, “Back off” when she hisses at the new kitten you’ve dared to bring home.

Ronnie wants to keep the kitten as far away as possible and deliver a clear message that it’s not welcomed in the house. She probably won’t attack the newcomer unless the kitten approaches her too closely.

Related: How to Introduce a Cat to a Dog (and to Another Cat)

#2“It’s mine! Don’t approach”

Max the Brown Tabby and Burt the Grey Kitten: Cat Argument 3

By nature, cats are lonely creatures, which protect their territory fiercely.

Don’t get me wrong. Cats don’t mind the company of other cats or animals as long as it’s on their terms.

What they hate is being forced to live with too many of their own kind with not enough room for personal space.

Remember that your home is your cat’s territory.

Ronnie rubs her head on the furniture and leaves scratch marks everywhere because she is announcing to whoever comes into the house that it’s already taken.

So, your cat will consider every new addition to the household as an intruder to her territory and will try to chase it away. Hissing is one way to do it.

READ MORE: Why Does My Cat Huff?

#3 I’m jealous!

territorial dispute

So, you’ve just brought a cute new kitten home. Think about the situation from the point of view of your cat:

  • She has to share territory and food with the kitty
  • You’re paying more attention to the kitten than to her
  • The kitty is occupying her favorite sleeping places and getting in the way

What I’m saying is that your cat is going to be jealous of the new kitten, especially if she has been your only cat so far.

It’s not easy to learn to share things, when you’ve never had to do it before, right?

Think on the bright side, hissing is actually better than outright violence or growling, because it means that your cat might learn to enjoy the company of the new kitten.

If you have an unneutered male, do not leave him alone with a small kitten under no circumstances.

Tomcats are more violent than females and have a strong territorial instinct. A small kitten is far too young to be able to protect itself from the male.

READ MORE: Why Do Cats Hiss at Other Cats?

#4 “You smell strange!”

I'll bite your nose off!

Sometimes cats might hiss at new kittens because the kitten smells unpleasant or strange.

Let’s say that you’ve just brought the kitten home after visiting the vet.

The little one probably will smell like the vet clinic – a smell your cat is familiar with and which she doesn’t like at all.

So, she is going to hiss at the new kitty because she is bothered by the smell.

READ MORE: Cat Growling in Sleep

# 5 “I’m not feeling well”


In case your cat suddenly starts hissing at the kitten, there might be something wrong.

Hissing is your cat’s way to warn the other kitten that it’s not in the mood for playing.

If you observe any strange behavior or if you suspect that your cat might be in pain, make an appointment with your vet right away.

Why mothers hiss at their kittens?

I’m sure that you’ve seen at least once how a mother cat hisses at her young. Even though it looks heartbreaking, that’s normal feline behavior.

The mother cat is saying “You’re old enough to take care of yourself.”

In other words, she is throwing the little ones out of the nest because she knows they have to learn to be independent.

Do not worry too much about your cat hissing at a new kitten.

Instead, introduce the cats slowly and give them time to get used to one another.

In time, they will find a way to co-exist and might even become friends.

What do you think about the matter? Why do cats hiss at new kittens? Tell us your thoughts in the comment section.

Grigorina S
Grigorina S

I’ve grown up surrounded by animals – dogs, cats, cows, goats, sheep, and horses and that has shaped me into what I am today – a crazy cat lady who always has a place for one more cat (or a dog). I’ve got two female cats – Kitty and Roni, and two tomcats – Blacky and Shaggy, but I also feed my neighbors’ cats when they come for a visit. I just can’t say no to them.

I discovered that writing is my vocation early in my school years. Since then I’ve taken part in several literature contests – writing horror and fantasy short stories and novellas.
For the past three years, I’ve been an ELS teacher, pouring my heart into showing children and teenagers how important English is for their future and trying to educate them how to treat their pets with care.

Find her on Instagram. Read her latest articles..

Learn more about Grigorina here