Aggression Between Family Cat

If the battles between your feline family members are anything like the struggle between Cain and Abel, there are a few things you can do to prevent the "sibling rivalry" from reaching biblical proportions. Of course, it's almost impossible to guess how well any particular pair or group of cats will ultimately tolerate each other; some unusually territorial cats may never adjust to sharing their house, and may do best in a one-cat family. But many aggression problems between cats can be successfully resolved, even if the two don't end up best friends when all is said and done. You'll need to commit time and effort to solve aggression problems between cats, and don't give up without consulting the appropriate experts.

Common Types of Aggressive Behaviors between Cats:

Territorial Aggression: Territorial aggression occurs when a cat feels that his territory has been invaded by an intruder. Cats are very territorial—much more so than dogs—and female cats can be just as territorial as males. The behavior patterns in this type of aggression include chasing and ambushing the intruder, as well as hissing and swatting when contact occurs. Territorial problems often occur when a new cat is brought into a household, when a young kitten reaches maturity, or when a cat sees or encounters neighborhood cats outside. It's not uncommon for a cat to be territorially aggressive toward one cat in a family yet friendly and tolerant to another.

Inter-male Aggression: Adult male cats normally tend to threaten, and sometimes fight with, other males. These behaviors can occur as sexual challenges over a female, or to achieve a relatively high position in the cats' loosely organized social hierarchy. This type of aggression involves much ritualized body posturing, stalking, staring, yowling, and howling. Attacks are usually avoided if one cat "backs down" and walks away. If an attack occurs, the attacker will usually jump forward, directing a bite to the nape of the neck, while the opponent falls to the ground on his back and attempts to bite and scratch the attacker's belly with his hind legs. The cats may roll around biting and screaming, suddenly stop, resume posturing, fight again, or walk away. Cats don't often injure one another this way, but you should always check for puncture wounds, which are prone to infection. Neutered males are much less likely to fight in this way—yet another great argument for having your animal sterilized.

Defensive Aggression: Defensive aggression occurs when a cat is attempting to protect himself from an attack he believes he cannot escape. This can occur in response to punishment or the threat of punishment from a person, an attack or attempted attack from another cat, or any incident that makes the animal feel threatened or afraid. Defensive postures include crouching with the legs pulled in under the body, laying the ears back, tucking the tail, and rolling slightly to the side. These responses are not the same as the submissive postures dogs show because they're not intended to "turn off" an attack from another cat. Continuing to approach a cat in this posture is likely to precipitate an attack.

Redirected Aggression: This type of aggression is directed toward another animal, or even a person, who didn't initially provoke the behavior. For example, a household cat sitting in the window may see an outdoor cat walk across the front yard. Because he can't attack the outdoor cat, he may instead turn and attack the family cat sitting next to him in the window.

What You Can Do

If your cat's behavior changes suddenly, your first step should always be to contact your veterinarian for a thorough health examination. Cats often hide symptoms of illness until they're seriously ill, and any change in behavior may be an early indication of a medical problem.

Spay or neuter any intact pets in your home. The behavior of one intact animal can affect all of your pets.

Start the slow introduction process over from the beginning. You may want to talk to an animal behavior specialist for help implementing these techniques.

In extreme cases, consult with your veterinarian about medicating your cats while you're working on a behavior-modification program. Your veterinarian is the only person who is licensed and qualified to prescribe medication for your cat, so don't attempt to give your cat any over-the-counter or prescription medication without some guidance. Animals don't respond to drugs the same way people do, and a medication that may be safe for a human could be fatal to an animal. Also keep in mind that medication, by itself, isn't a permanent solution, and should only be used in conjunction with behavior modification.


What Not  to Do

If your cats are fighting, don't allow the fights to continue. Because cats are so territorial, and because they don't establish firm dominance hierarchies, they won't be able to "work things out" as dogs sometimes do. The more often cats fight, the worse the problem is likely to become. To stop a fight in progress, make a loud noise (like blowing a whistle), squirt the cats with water, or throw something soft at them. Don't try to pull them apart.

Prevent future fights. This may mean keeping the cats totally separated from each other while you're working on the problem, or at least preventing contact between them during situations likely to trigger a fight.

Don't try to punish the cats involved. Punishment is likely to elicit further aggression and fearful responses, which will only make the problem worse. If you attempt to punish either combatant, you may even become a target for redirected aggression.


Because their social organization is somewhat flexible, some cats are relatively willing to share their house and territory with multiple cats. It's not uncommon for a cat to tolerate some cats, but not get along with others in the house. But the more cats who share the same territory, the more likely it is that some of your cats will begin fighting with each other.

When you introduce cats to each other, one of them may send "play" signals that can be misinterpreted by the other cat. If those signals are interpreted as aggression by one of the cats, then you should handle the situation as "aggression" and seek professional help right away.

There are many factors that determine how well cats will get along with one another, but even animal behavior experts don't fully understand them. What we do know is that cats who are well-socialized (those who had pleasant experiences with other cats during kittenhood) will likely be more sociable than those who haven't been around many other cats. On the other hand, "street cats," who are in the habit of fighting with other cats to defend their territory and food resources, may not do well in a multi-cat household.

© 2002. Adapted from material originally developed by applied animal behaviorists at the Dumb Friends League, Denver, Colorado. All rights reserved.

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Positive Reinforcement: Training Your Cat with Treats and Praise

We all like to be praised rather than punished. The same is true for your cat, and that's the theory behind positive reinforcement. Positive reinforcement means giving your pet something pleasant or rewarding immediately after she does something you want her to do. Because your praise or reward makes her more likely to repeat that behavior in the future, it is one of your most powerful tools for shaping or changing your cat's behavior. It's more effective to teach your pet what she should do than try to teach her what she shouldn't.
Correct timing is essential when using positive reinforcement. The reward must occur immediately—within seconds—or your cat may not associate it with the proper action. For example, keep some pieces of dry cat food in your pocket; when your cat uses her scratching post, you can throw a piece for her to chase as a reward. Many cats enjoy chasing (hunting) their food and it's good exercise, too. If you throw the food when she has stopped scratching the post and she is walking towards you, she will think she's being rewarded for coming to you.

Consistency is also an important element in training. Everyone in the family should reward the same desired behaviors.

Using Positive Reinforcement

For your pet, positive reinforcement may include food treats, praise, petting, or a favorite toy or game. When your pet is first learning a new behavior, such as clawing the scratching post instead of your couch, she should be rewarded every time you catch her using her scratching post. You may even help shape her behavior of using the scratching post by spraying it with catnip (if she reacts positively to catnip) or enticing her with a toy that you dangle on the post. This will excite her and cause her to claw at the toy (and the scratching post).

Conversely, avoid taking her over to the scratching post, positioning her paws on the post, and raking them along the post to show your cat what she's supposed to do. This will likely have the opposite effect and make her less likely to use the post. She may interpret your actions as frightening and uncomfortable. It's important to look at the world from her point of view.

Once your cat reliably offers the desired behavior, you may reward her with treats intermittently—for example, three out of every four times she does the behavior. Then, over time, reward her about half the time, then about a third of the time, and so on, until you're only rewarding her occasionally with a treat. Continue to praise her every time. Your cat will learn that if she keeps offering desired behaviors, eventually she'll get what she wants—your praise and an occasional treat. You won't be forever bound to carry a pocketful of goodies, but it's fun to surprise your cat from time to time.

The Pros and Cons of Punishment

Punishment can be verbal, postural, or physical and is meant to make your pet immediately associate something unpleasant with a behavior you don't want her to engage in. The punishment makes it less likely that the behavior will occur again. To be effective, punishment must be delivered while your pet is engaged in the undesirable behavior—in other words, "caught in the act." If the punishment is delivered too late, even seconds later, your pet will not associate the punishment with the undesired behavior. The punishment will seem totally unpredictable to her.

Remember, cats do not act out of spite or revenge and they don't have a moral sense of right and wrong. Never use physical punishment that involves discomfort or pain; in addition to being inhumane, such punishment may cause your cat to bite, defend herself, or resort to other undesirable behaviors. For example, holding your cat's neck skin and shaking her may result in a frightened cat who scratches or bites to defend herself.

Also, your cat might associate the punishment with other stimuli, including people, who are present at the time the punishment occurs. For example, a cat who is punished for getting too close to a new baby may become fearful of, or aggressive to, that baby—or to other babies. That's why physical punishment is not only bad for your cat, it's also bad for you and others.

It's easy to understand that punishment delivered by you may erode your cat's trust and frighten her. That's why punishment is most effective when it does not come directly from you. For example, if your cat enjoys scratching the couch, you may apply special double-sided tape to those surfaces. Cats rarely like sticky paws. Thus your cat perceives the couch, and not you, to be delivering the punishment. In this way, too, your cat is more likely to avoid the undesirable behavior even when you're not around. However, it is critical that while discouraging undesirable behaviors, you help your cat understand what you want her to do and provide appropriate outlets for her normal cat behaviors. (For more information on specific tools and techniques to keep your cat away from particular places or to stop her from engaging in certain behaviors, see our tip sheet on Using Aversives to Modify Your Cat's Behavior.)

One of the reasons that cats are such fun companions is that when they're not sleeping, many of them enjoy playing. Playing with your cat will not only help her physical and behavioral development, but it can also reduce undesirable behaviors. Be sure your cat has safe toys to play with by herself, and don't underestimate the power of playing with your cat to strengthen the bond between you and enhance the quality of life for both of you.

© 2002. Adapted from material originally developed by applied animal behaviorists at the Dumb Friends League, Denver, Colorado. All rights reserved.