Why Cats Fight: 5 Common Triggers for Feline Aggression

Cats fight due to territorial disputes, social hierarchy, and inadequate socialization. Learn what to do for each situation.

Updated June 6, 2023
Two cats fighting outside.

If your cat is fighting with other felines around the neighborhood or even in your home, it's can be hard to figure out the reasons for this problem behavior. Rule out these five common reasons for cats fighting so you can address the situation and help your cat lead a more peaceful existence.

Cat Fights as a Result of Territorial Aggression Inside

Cats are very sensitive to changes in their environment, and this includes adding a new cat or kitten in to the household. If you don't properly introduce the cats with lots of baby steps and positive reinforcement, you can create a conflict between the cats, which may involve fighting.

Likewise, sometimes two cats may seem to get along if one is younger, but as that cat reaches social maturity, aggression may occur by the older or younger cat, or sometimes from both equally regardless of sex.

How to Prevent It

The best way to prevent this from happening is by introducing new cats to each other the right way to minimize stress and increase positive experiences for both cats. Cats should be given lots of time to acclimate to each other, with plenty of space to move away, including vertical space such as cat trees, wall perches, and places to hide.

In the beginning, you want to keep them in separate rooms so they can only smell and hear each other. Slowly increase their access to each other while pairing it with things they enjoy, like treats, toys, and brushing.

Quick Tip

If you find yourself with two cats who previously got along but who are now fighting, treat them as "brand new cats" and go through the introduction from the start.

Cat Fights Resulting From Territorial Aggression Outside

If you have an indoor-outdoor cat, your cat may get into fights with other cats that come near or into your property boundaries. This is because of cats' territorial natures.

Tips to Control It

Keeping your cat indoors is one way to eliminate these types of fights. You can provide your cat with window enclosures and outdoor "play rooms" to let him or her have some outdoor time but still remain safe from other cats and predators. You can also try ways to keep the other cat or cats from entering your yard, although this can be difficult to do depending on your yard, fencing, and neighbors' willingness to control their cats.

Mating-Related Aggression Cat Fights

If you have more than one male cat and one or more of them are not neutered, you may experience fighting during feline mating season. Males will fight with each other over access to a female cat even if you don't happen to have a female cat in your home. It's possible they can sense females in heat nearby in neighboring homes or stray female cats roaming outside.

How to Stop It

Neutering all male cats can help reduce this type of aggression and unpleasant spraying behavior that may accompany it.

Maternal Behavior

Another form of aggression between cats is related to female cats who have just birthed a litter. If other cats walk near the litter, the new mom may become aggressive to protect her kittens.

Ways to Control It

In these cases, the aggression should subside as the kittens become weaned, but you should give the mom and her new babies a quiet place free of other cats until she's comfortable. Spaying, of course, will also prevent this behavior in the future.

Female Cat Fighting With Male Cats

In some cases, female cats will fight with male cats in or around the home. This could be because the female does not want to mate with them. Male cats can become persistent or aggressive in their attempts to mate, causing a female cat to defend herself aggressively. Or, the female cat may not get along with the male cat just because she doesn't want him in her territory.

Ways to Control It

If your female cat is fighting with male cats, you may need to separate your female from the other cat. This is particularly true if it's mating time. If the male cat wants to mate and she doesn't, keep them away from each other until the female's heat cycle is over.

Redirected Aggression

Cats that are stressed by stimuli in their environment can "redirect" their anxiety onto another cat, which often takes the form of aggression. Hearing a scary noise or seeing another animal outside the window are the types of stressors that can cause a cat to redirect aggressively onto another.

How to Handle It

In this scenario, you will want to identify the stressor that is triggering the behavior and try to remove it, although that isn't always possible if it is a temporary event such as outside construction noise. Give both cats some time apart to de-escalate, and if need be, do the re-introduction process again.

Play Fighting Behaviors

Two kittens play-fighting.

Many species of animals will play with each other by fighting, and it may look scary but be perfectly fun behavior for both of the cats. However, play fighting can slide into actual fighting if one or both cats becomes over-aroused and agitated.

Because play is a great outlet for any animal, you don't want your cats to stop play fighting if they are truly enjoying it, so you should supervise play of this type and look for signs outside of the ordinary. Move to distract the cats if the play fighting starts to escalate.

Quick Tip

Watch for tense body language, growling, or hissing in cats who are playing. When the hairs on their backs stand up and they look frightened, something more serious may be going on.

Handling Inter-Cat Aggression

It's very important to know what to do to stop your cats from fighting. Never intervene physically as you can get seriously hurt and avoid using anything aversive, as this can make the cats even more aggressive toward each other. Rather, focus on distracting and separating them, then working on ways to reintroduce them and provide positive outlets for their behavior.

Why Cats Fight: 5 Common Triggers for Feline Aggression