How to Introduce Cats and Help Them Become Friends

Cats are territorial animals that evolved as solitary hunters. Each cat needs its own places to rest, sleep, eat, go to the bathroom, hunt and watch the world. So when a new cat arrives, conflict with the resident cat is almost inevitable at first. How do you help your cats become friends and live together peacefully? That’s the main question we’ll answer here.

In this article, you’ll learn how to introduce cats to each other, how to help them get used to living together and what to do to avoid conflict.

Prepare Your Home

To minimize problems when a new cat arrives, prepare your home in advance. Here’s how to create a comfortable environment for both the new and the resident cats:

1. Give each cat its own resources: food and water bowls, a bed or hideaway and litter boxes. The usual rule is one litter box per cat, plus one extra, placed in different parts of the home. This reduces competition and stress.
2. Place food bowls in separate spots, ideally out of sight of each other at first. Mealtimes are when cats feel the most competitive and tense, so each cat should be able to eat without feeling watched or threatened.
3. Create separate high places for each cat: cat trees, wall shelves and window perches. Cats love to watch what’s going on from above, and vertical space lets them share a room without being too close.
4. Provide hiding places, tunnels, boxes with several openings and play structures. They should be spacious, with more than one exit, so a cat can always get away from the other cat. Cats need to feel safe.
5. Buy the new cat its own toys and bedding. At first, don’t use your resident cat’s toys to play with the newcomer.
6. Be ready to give all your cats equal love and attention. Jealousy can trigger conflict.

The First Meeting: How to Introduce Cats

The first introduction is very important. Prepare carefully and don’t leave it to chance. How your cats will get along in the future depends a lot on how well you manage this stage.

What Cat Behavior Experts Recommend

1. Start with separation. Keep the new cat in its own room (a spare bedroom or a quiet office, with food, water, a litter box, a bed and toys) for at least several days, and often a week or two. This “base camp” lets the newcomer settle in, and your resident cat can get used to its smell under the door.
2. Use your scent as a go-between. Give the new cat a T-shirt you’ve worn to sleep on, then give it to your resident cat.
3. Swap scents. Cats have scent glands on their cheeks that release pheromones, which tell cats about each other and help reduce anxiety. Gently rub a soft cloth on one cat’s cheeks, then offer it to the other cat to sniff. Swap their bedding from time to time, and let each cat explore the other’s area while the other is shut away.
4. Feed them on opposite sides of the closed door, so they associate each other’s smell with something good. Gradually move the bowls closer to the door.
5. Let them see each other. When both cats are calm about each other’s scent, open the door a crack, use a baby gate or a screen door, or let them see each other through a glass door. Keep these sessions short and pair them with treats or meals.
6. Supervise the first face-to-face meetings. Only allow them to meet once you see calm, mutual curiosity: relaxed bodies, slow blinking and sniffing.
7. As soon as you see signs of aggression (staring, growling, hissing, flattened ears, swishing tail), calmly end the session and go back a step. It takes time for cats to learn to be relaxed in each other’s company.
8. Don’t single out one cat. Your cats should feel that you treat them equally. This reduces competition.
9. During the first meetings, keep interior doors open and windows closed, so the new cat can escape and hide if there’s aggression.
10. Don’t rush. Give your cats time to get used to each other. Leave them alone together only when you’re sure they won’t fight.
11. Help your cats bond through play. Use wand toys to play with both cats at once, at a comfortable distance from each other. Praise them and give them treats when they play calmly together.

Important: trim your cats’ claws before their first meeting to reduce the risk of injury.

A Male and a Female Cat

A male and a female cat often get along fairly quickly. Fights are usually less intense, because they don’t compete in the same way. But if the cats aren’t neutered, an intact male will constantly be trying to mate, and an intact female will go into heat repeatedly. Both cats will be constantly stressed, and you’ll soon have kittens.

That’s why the most important factor for a male and a female cat living together is spaying and neutering. Have both cats fixed. This prevents unplanned litters and makes it much easier for them to become friends.

An Adult Female Cat and a Kitten

This is often one of the easiest combinations. Many adult cats are fairly tolerant of a newcomer that’s small and unthreatening, and some even look after the kitten. An adult cat can teach a kitten a lot about cat life. Still, follow these rules:

• Don’t make your resident cat jealous: give it affection whenever it wants.
• Don’t let the kitten eat from the adult cat’s bowl or use its litter box.
• Don’t allow the kitten to do things the adult cat isn’t allowed to do.
• Don’t leave them alone together at first.
• Make sure your older cat has kitten-free places to rest. A kitten’s endless energy can be exhausting for a senior cat.

An Adult Male Cat and a Kitten

Many neutered males are very tolerant of kittens, and some become wonderful “uncles.” But an unneutered male may see any newcomer as a rival, even a small one, and may become aggressive and start marking his territory. In that case, introductions need to be slower and more careful:

• At first, keep the kitten in a separate room that the adult cat doesn’t enter. Don’t leave them alone together.
• Let the adult cat into the kitten’s room from time to time, so he gets used to its smell. Move the kitten to another room while he does.
• The first meeting should be supervised. If the adult cat is aggressive, separate them and try again in a few days, more gradually.
• Don’t let the kitten eat from the adult cat’s bowl, so he doesn’t see it as a rival for food.
• Neutered cats are much more peaceful. Have your cat neutered before you bring a new kitten home.

Young cats tend to get along best. If you’re planning to have two cats, consider adopting two kittens together, such as littermates. Make sure both are spayed or neutered.

How to Stop Aggression Between Cats

Aggression is a normal reaction to stress, a rival or an unfamiliar animal. It’s driven by instinct, and you can’t always predict or prevent it. But when cats live together, you can and should step in to help them make peace. Do it carefully, wisely and at the right time.

Causes of Aggression

Cat behavior experts identify several main causes of aggression between cats:

1. Competition over status and resources.
2. Conflict between resident and new cats.
3. Territorial behavior: cats may fiercely defend their places for eating, sleeping and going to the bathroom.
4. A new smell. After a trip to the vet, a cat brings back unfamiliar smells, which can make the other cat treat it as a stranger. This is called “non-recognition aggression.”
5. Feeling unwell. Pain and illness change behavior, and a sick cat may become more irritable.
6. Redirected aggression: a cat that’s upset by something it can’t reach, such as a cat outside the window, may attack its housemate.
7. Stress. Any stressful situation affects cats’ behavior.
8. Personality clashes. Like people, cats are all different, and they don’t have to like each other.
9. Maternal aggression: a mother cat protecting her kittens.
10. Play fighting. During play, cats may chase, pounce, nip and ambush each other. This is normal if both cats take turns and neither is hurt or afraid.

Every situation needs its own approach. But if your cats are fighting and biting, don’t ignore it, and don’t assume they’ll work it out themselves. These tips will help stop aggressive behavior and protect your pets from physical and emotional harm.

Tips for Stopping Aggression

1. Interrupt a fight safely. Never use your hands to separate fighting cats: you could be badly bitten or scratched. Instead, make a sudden noise (clap your hands loudly), or slide a large cushion or a piece of cardboard between them. Don’t punish either cat.
2. Spay and neuter your cats. Unneutered males are the most aggressive.
3. Reduce competition. Give each cat its own food bowls, litter boxes, beds and resting spots, in different places.
4. Create plenty of hiding places and high spots for resting and watching.
5. Use pheromones. A plug-in diffuser designed for multi-cat homes, such as Feliway Friends (Feliway MultiCat in some markets), can reduce tension between cats.
6. If the aggression is serious, separate the cats into different rooms and start the introduction process over from the beginning. Swap their rooms from time to time so they keep getting used to each other’s scent.
7. Play with each cat separately every day, so they can burn off energy and don’t take it out on each other.
8. Talk to your vet. They can check for medical causes and, if needed, prescribe medication or calming supplements, or refer you to a veterinary behaviorist.

How Long Does It Take for Cats to Become Friends?

Getting used to each other can take anything from a few days to several months, and sometimes up to a year.

Be patient and help your cats, above all by showing equal love and affection to everyone in your home. If you can’t solve the problem yourself, talk to your vet or a qualified cat behaviorist. In rare cases, two cats never accept each other and would need to live completely separately. In that situation, it may be kinder to find one of them a new home. Read more: how to rehome a cat responsibly.

Sources:

• ASPCA: Aggression between cats in your household
• wikiHow: How to encourage multiple cats to get along
• PetHelpful: When cats don’t get along