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Why Does My Cat Hiss and Growl at Strangers? (7 Potential Reasons)

Abyssinian cat hisses

Feline emotions are mysterious and often misunderstood by pet parents. Compared to dogs, cats are better at hiding their fears, and they make it harder for owners to determine the source of the behavior. However, you can study your pet’s body language for clues about its distress. Understanding what upsets your cat will help you calm it down and reduce future occurrences.

When your cat growls or hisses at guests, your first reaction may be to yell or chase the animal out of the room. While this may be a temporary solution to make your guest feel comfortable, it does not address the cause of the aggression. Before labeling your cat as a psychopath, you can examine why your cat may be acting aggressively towards strangers.


The 7 Potential Reasons Why a Cat Hisses and Growls at Strangers

1. Territorial Aggression

Like most animals, cats establish territories that may include the entire house or only sections of it. Although males are usually more aggressive about their boundaries than females, both sexes can display aggression towards strangers or unfamiliar visitors. When a cat feels uncomfortable or threatened by a new presence in the home, it may respond by hissing, growling, or even attacking the stranger.

Some of the circumstances that can encourage more territorial aggression include:
  • A new pet in the home
  • A change in the environment like moving to a new residence
  • Returning home from a long trip

How to remedy the problem:

Create a place where your cat can hide when it feels uncomfortable. You can set up a cat condo or a cozy bed in a quieter area of the home that will serve as a refuge for your pet within its territory. Ask your guests to avoid approaching the cat or petting it until the animal becomes more accustomed to their presence.

cat hissing
Image Credit By: yvonneschmu, Pixabay

2. Maternal Aggression

Females are protective mothers that will lash out at anyone who approaches their kittens. If your feline is usually calm and friendly towards all humans, it can still show aggression while raising its offspring. It can take 4 to 6 weeks for kittens to be weaned from their mother’s milk, and mothers may display aggression towards strangers until their kittens become more independent.

How to remedy the problem:

Keep the cat family in another room far away from the area where your guests congregate. Create a comfortable and noise-free environment for the animals and prevent strangers from approaching the kittens until the mother seems less protective of her children. You may have to wait a month or more for the mother to tolerate visitors near her family.

3. Fear Induced Aggression

When a cat is fearful of someone in your home, it may display a combination of defensive and offensive aggression. When cats show a defensive stance, they will flatten their ears, tuck their tail in, and roll on their side. However, if the visitor does not go away and continues to irritate the animal, it may turn to offensive tactics such as hissing, growling, or swatting at the person.

How to remedy the problem:

Grabbing your cat or yelling can increase its aggression, and the cat may turn to strike you. Ask your guest to join you in another room and allow your cat to calm down before approaching it. You can introduce your cat to the stranger in small steps by keeping the cat and visitor apart in subsequent visits and gradually decreasing the distance between them. Reward your pet with treats when it does not get upset when visitors enter your home.

angry cat hissing
Image Credit: Fang_Y_M, Pixabay

4. Pain Induced Aggression

Sudden aggression towards a visitor or family member is shocking to owners, especially when the cat is ordinarily sweet and good-natured towards all humans. A common cause of sudden aggression in cats is an illness, and pain can turn a lovable cat into a fearful and paranoid animal. Several medical problems, including trauma, arthritis, infections, and dental issues, can lead to aggression.

How to remedy the problem:

Your veterinarian can help you determine why your cat is misbehaving. A complete examination and additional tests may be required to diagnose your pet’s condition. When the illness is treated and the animal recovers, it should be more comfortable around strangers.

5. Redirected Aggression

Although it may seem like your pet is targeting a guest that it does not trust, the aggression could be related to another situation or animal that’s upsetting the cat. If a stranger approaches when your cat is staring out of the window at a bird or other animal in the yard, it can redirect its anger towards that person. The cat may see the person as someone who is interrupting its hunting prospects. A loud noise like a sonic boom or firework explosion may also upset the cat, and a stranger approaching when it’s scared may be met with hissing or striking.

How to remedy the problem:

Different breeds have varying prey drives, and some cats are more likely to act aggressively when their predatory nature is challenged. Ask your friends to stay away from your pet when it’s staring at prey and set up a cat bed or condo in a room your pet can use to escape loud noises. If your cat has severe anxiety, talk to your veterinarian to see if your pet needs anti-anxiety medication or supplements.

a kitten hissing
Image Credit: Marlon Soares, Unsplash

6. Petting Induced Aggression

You may have noticed your cat’s attitude abruptly shifts when it’s being petted. Some cats will purr and roll around and then strike or growl at the person petting them. Petting-induced aggression is not entirely understood by veterinary behaviorists. However, some veterinarians speculate that cats become irritated by repetitive motions. If someone rubs the same area repeatedly, the cat may have had enough and decide to warn the petter with a hiss or strike from its paw. Although most well-behaved cats enjoy petting, some merely tolerate it.

How to remedy the problem:

Watch your cat’s body language while it’s being petted. The switch from lovable to aggressive may seem sudden, but you can look for signs the cat is becoming annoyed before it lashes out. If its ears are pulled back and its eyes are partially dilated, it could be signaling the petting should end. Every cat has a different tolerance for human contact, and you may have to ask your guest to limit how long they touch your pet.

7. Idiopathic Aggression

Aggression in felines is a complex subject that behaviorists and doctors have worked tirelessly to understand. Although the causes of deviant behavior are clearer, some aggressive acts are difficult to classify. When a veterinarian has ruled out medical and behavioral problems, it may diagnose your pet with idiopathic aggression. That means that the cause of the aggression cannot be explained by the patient’s history or medical status.

How to remedy the problem:

If your cat’s aggression is unprovoked and out of control, you should visit a veterinary behaviorist. Unfortunately, many pet parents take their angry cats to shelters out of fear. Roughly 27% of all felines taken to shelters by their owners were due to aggressive behavior. It may take time to calm your cat, but a specialist may suggest relaxing supplements, increasing exercise sessions, or rearranging your home to make the animal more relaxed.

a tabby mackerel cat hissing
Image Credit: strh, Pixabay


Tips for Preventing Escalating Aggression in Cats

We’ve touched on some of the methods of reducing feline aggression, but here are a few additional suggestions for handling an angry cat.

  • When your cat hisses at a visitor, ignore the behavior and calmly escort your guest into another room.
  • Avoid yelling or throwing something at the cat. Verbal or physical abuse will only increase fear and may cause your cat to become more aloof and moody.
  • Ask your friends not to approach your cat until the animal has seen them several times and feels more comfortable about them.
  • Ensure that your cat’s condo or bed is in a quiet area of the house.
  • Keep the litter box in a quiet room away from loud machinery.
  • Play games with your cat every day and ensure it gets enough exercise while considering its age and health.
  • Feed your cat a well-balanced diet with premium cat food and fresh water.
  • Introduce new pets to your cat gradually. Keep the creatures separated for the first few weeks and place their food bowl in separate rooms.
  • Reward your kitty with a treat when it acts friendly to a stranger that it once hissed at.
  • Visit the veterinarian at least twice a year to ensure your cat stays healthy and happy.



A grumpy cat is amusing to some people, but aggression is not a behavior you want to see in your pet. Cats are small creatures, but their sharp claws and fangs can cause considerable injuries to unsuspecting humans. Determining the reason for the behavior is a priority, but you cannot expect your pet to change overnight. Cats take longer to relax after a frightening occurrence than dogs, and it may take days or weeks for your cat to accept a new face in the house. However, your vet can assist in keeping the animal relaxed and preventing injuries to your guests.

Featured Image Credit: Slava Dumchev, Shutterstock

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