How to introduce two cats and manage to keep the peace at home - Resources

How to introduce two cats and manage to keep the peace at home

Whether you want to introduce two adult cats or introduce a kitten to a cat, here are step-by-step details for success.

As any cat-owning friend will tell you, felines bring an abundance of comfort, hilarity and companionship to a person’s life. With so much joy a single cat brings to a household, it’s natural to assume that two kitties would result in double the fun. Right?

Not so fast, says Crista Coppola, who holds her doctorate in animal sciences and is a certified cat and dog behavior specialist with

“Cats have an avoidance-based hierarchy system and are non-obligatory social animals,” she explains. What this means: Like many of their big kitty cousins, cats don’t necessarily work in teams like dogs. Rather, they prefer to function solo most of the time. 

Coppola explains that, in the wild or even with feral cats, this is no problem — cat #1 establishes dominance over a certain territory, and cat #2, sensing this, simply backs off sans confrontation. But problems may occur in a home where cat #2 can’t roam free and establish his own dominance in a different territory.

“In a non-captive environment (outside), a cat would simply leave,” she says. “In a captive environment (home), they are unable to leave and are then forced to be in the presence of one another.” 

In other words, whereas the two kitties could’ve gone their separate ways peacefully, now, there’s a forced hierarchy square-off. And as many dual cat owners can attest to, this meeting isn’t always pretty, resulting in hisses, growls or worse, serious injuries. 

That being said, it is possible to cohabitate with two or more kitties drama-free. But as Coppola explains, you have to take a great deal of care when executing the introduction. Any deviation could mean the cats will be sparring for as long as you keep them together. 

Here, Coppola and other experts outline exactly how to introduce two cats to one another. 

How to introduce two adult cats 

1. Harness training 

As Coppola explains, harness training a cat (meaning simply getting them comfortable with a harness and leash) can provide physical backup should the kitties get into a physical altercation down the line. 

Although Coppola says that the time to harness-train a cat is usually dependent on the cat, a few months prior to bringing in a new kitty, get the initial cat comfortable with a harness twice per week for 15-minute sessions. Here’s how:

  • Get the cat comfortable wearing the harness during meals. “I recommend waiting until before the cat’s mealtime, then placing the harness on — gently and loose enough so as to not feel constricting but tight enough that it won’t fall off,” says Coppola. “Once the harness is on, immediately give your cat wet food.” She says that once mealtime is up, remove the harness. Repeat this step two to three more times, or until your cat is unbothered by the harness. 
  • Next, place the harness on the kitty during playtime. “Engage in some play, roughly two to 10 minutes, with your kitty while he wears the harness,” suggests Coppola. “This activity will help him acclimate to the feel of the harness as he moves.” She recommends repeating this step three to five times, or until your cat is unbothered by the harness.
  • Don’t wait for the new cat to arrive to harness-train the resident kitty. “You don’t want your cat to associate harness-training with the new cat. This would be an additional stressor.” 

2. Set up separate locations for each cat

Prior to your new cat’s arrival, it’s important to ensure each cat has their own separate, secure location to feel comfortable (and distanced) from one another, says Coppola.

“This is usually through the use of double-stacked baby gates in a doorway,” she explains, noting that you can also simply separate the cats into different rooms (if possible). Here’s what to stock in each cat’s area:

  • Food and water 
  • A bed 
  • A litter box
  • A scratching area and toys 

“Your cats need to start out completely separate in their own rooms. Neither cat can enter the other’s space. And they need at least a day or two to get used to their new spaces before the next step.”


3. Bring your new cat directly into the new area

On the first day of introduction, bring your new cat, ina carrier, into their new location while your existing cat is secured in their respective location. Coppola says to close the door or shut the gate behind you, placing the carrier near the food, water and litter box. 

Open the carrier and allow the new cat to exit in his own time and voluntarily, she suggests. “Allow the new cat to explore and become entirely comfortable in his area,” she adds.

A key component to success during this stage, says Sharon Williams, a pet behavior specialist, and for all remaining steps, is patience. 

“Your cats need to start out completely separate in their own rooms,” she says. “Neither cat can enter the other’s space. And they need at least a day or two to get used to their new spaces before the next step.”

Some key comfort signs, according to both Williams and Coppola? Each kitty is eating and drinking and using their litter box.  

4. Start the scent exchange 

As Williams and Coppola note, scent is an enormous component to ensuring both cats’ comfort in a new, potentially scary, situation. “Cats are also territorial and extremely sensitive to scent,” Coppola adds. “The arrival of a new cat can disrupt the homeostasis of the household and cause stress.”

The solution to help ease this tension, both Williams and Coppola say? Start a scent exchange. Here’s how:

  • Take the bedding or toys from Cat #2’s room and place it in Cat #1’s room. Leave in Cat #1’s room for a few hours or even days (the longer you draw out this process, the better, our experts say). “Allow the resident cat to investigate all of the smells of the new cat,” says Coppola.  
  • Do the same for cat #1’s scent in cat #2’s room. Leave the item in the kitty’s room for a few hours or days. 
  • Associate positivity with the new cat’s smell. Williams says that, as you leave the other kitty’s item in each room, bring the first cat copious treats and catnip. 
  • Allow each cat to explore the other cat’s area. The key for this to work, according to Williams? Ensure the other cat is completely out of the room first. 

5. Allow both cats to see, but not touch, one another

Coppola says that, once the new cat shows increasing signs of comfort (meaning you see no accidents outside of the litter box, eating and drinking on a regular schedule), it’s time to start thinking about physical (or, rather, visual) introductions. 

“You can start by opening the [door to the room] slightly to allow for visibility,” Coppola explains, noting that stacked gates can make this step even easier. “Allow the cats to ‘meet’ each other through the gate voluntarily.” 

Coppola says that this first interaction can be a testy one. “If the cats charge or hiss at each other through the gate, reduce the visibility and allow for more separation time before trying again.” She says that, on your next try, give treats you know each kitty has a preference for to associate positivity with the meeting. 

Unfortunately, as Coppola explains, this step could take some time. But it’s key to not move on to the next step  until both cats only show curious — but not hostile or aggressive — behavior. 

6. Start a physical meeting

“Once both cats are voluntarily and comfortably spending time at the gate with each other, you can try them together in a more open space,” says Coppola. “Start by allowing just a few minutes of strictly supervised interactions and make sure there are always options to escape for each of the cats.” 

Be sure to have plenty of treats, as well as distractions (like toys) on hand. Coppola notes that it may be beneficial to have a harness on cat #1 (if they were trained to use it), just in case any chasing occurs. 

“Supervise [interactions] closely, and watch their body language carefully,” adds Williams. “Distract the cats if they start to stare intently at each other.”

Williams notes that it’s also good to keep a time limit on the initial physical meetings — no more than five to 10 minutes roughly three to five times per day. “If you start to notice either cat becoming overwhelmed, shorten those sessions.” 

7. Keep their living quarters separated and continue interactions

As both Coppola and Williams note, timing for success with introducing two cats is highly variable, as no two felines (and their pairings) will be alike.

But so long as you stay consistent, and continuously monitor both cats’ behavior, there should be light at the end of the tunnel. 

“It would be best to keep the cats living in separate areas for the first week, with all interactions being supervised,” Williams explains. “Sessions can be extended gradually as each day goes by. Eventually, you’ll be able to leave them alone in a room so long as you always keep an ear out.”

Eventually, Coppola says that you can keep cats together in the daytime, but secured at night, as cats tend to be active at night. 

But generally, just stay patient. “These steps could take days or weeks depending on the cats, their individual temperaments and previous experiences,” Coppola says. “Keep in mind that it’s far better to err on the side of caution and take it slowly as a bad interaction can sometimes be very difficult to come back from.” 

Introducing a kitten to a cat 

Although Coppola notes that the introduction phase between kittens and adult cats tends to be similar to adult cat introductions, the process will likely be a bit speedier. 

“Generally speaking, introducing a kitten to an adult cat is usually easier, especially if the older cat has had previous successful interactions with cats and kittens,” she explains. “But the same precautions and steps should be used.” 

Coppola says that you might want to consider using a mesh pen to help introduce a cat and a kitten in place of separate rooms. “This would likely not work with two adult cats,” she points out. “Open-top pens are typically only ideal for kittens. Adult cats are far more likely to jump out of a pen whereas kittens are less physically capable.”

Introducing a feral cat to another cat

For feral cats, Coppola warns that introduction to other felines could be considerably difficult. 

“The feral cat is not likely to have had many previous social interactions in such close and sustained proximity,” she explains. “Additionally, a previously feral cat would not only meet a new cat, but he would be attempting to acclimate to an entirely new life with human interaction, captivity, litter box use and lack of freedom.”

Coppola says that, while it’s not impossible to introduce a feral cat to a domesticated one, expect the steps outlined above to take double, even triple, the amount of time.

How to know if two cats simply can’t coexist in the same home

So, you’ve brought cat #2 home and have gone through weeks, even months, of aggressive interactions — and no success. Is there ever a point at which you have to conclude that two cats won’t be able to peacefully coexist?

“It’s hard to say never, but in general, if cats are fighting to the point where one or both is injured or hiding notstop, the owner should look into re-homing one of the cats,” Coppola says. “When the household harmony is disrupted, it can be extremely stressful for the cats and their welfare, both physical and mental.” 

Coppola notes that some warning signs for stress overload in cats include: 

  • Inappropriate elimination (so going outside of the litter box) 
  • Self-injurious behaviors, like psychogenic alopecia (overgrooming themselves) or skin irritation 
  • Other strange behaviors, like sudden hiding or a loss of appetite 

If you do need to rehome a cat, advertise that you’re offering adoption among your social circles and on social media. You can also check with local shelters to see if they’d be willing to take the kitty. The Shelter Pet Project offers a tool to find local shelters that may be willing to take in your kitty near you. As a last resort, you can also “surrender” the kitty to your local humane society. 

That being said, the above should be considered only if either of the kitties, or you or a family member, are in danger. In all likelihood, with the proper introduction, there’s no reason why you can’t live harmoniously with two cats under the same roof.