Why a Slow Introduction Matters

Cats are territorial by nature, and an older cat who has had the run of the house for years will not necessarily welcome a small, bouncy stranger with open paws. Kittens, meanwhile, are curious, fearless and full of energy — a combination that can feel overwhelming to a settled adult. Rushing the process is the single most common reason introductions go badly, and it can lead to hiding, spraying, appetite loss and long-term tension between the two.

The good news is that cats are also highly adaptable. With patience and a structured approach, most adult cats will eventually tolerate, and often genuinely enjoy, a new companion. The aim is not to force friendship but to build positive associations, one small step at a time.

Before the Kitten Comes Home

Set up a separate "safe room" for the kitten before you collect them. A spare bedroom or a quiet bathroom works well. This room should contain everything the kitten needs: a litter tray, food and water bowls, a scratching post, a cosy bed and a few toys. It should be somewhere the older cat does not sleep or eat, so there is no competition over resources from day one.

• Book a vet check for the kitten within the first few days — they may need vaccinations, worming and flea treatment before mixing.
• Make sure your older cat is up to date with their own vaccinations and health checks.
• Provide at least two litter trays in different locations once the cats share space, plus separate feeding stations.
• Wash your hands and change your clothes after handling the kitten, so you don't transfer unfamiliar smells onto your resident cat.

Week One: Scent and Sound Only

For the first few days, the cats should not see each other at all. This stage is about scent. Rub a soft cloth gently around the kitten's cheeks and body, then let your older cat sniff it while you offer a treat or a bit of gentle stroking. Do the same in reverse, so the kitten becomes familiar with the resident cat's smell.

Feeding cats on opposite sides of a closed door is one of the most effective tools available. Start with the bowls a metre or so back from the door, and over several days move them closer as long as both cats stay relaxed and eat normally. If either cat stops eating, walks away or hisses, you have moved too quickly — simply go back a step and stay there a little longer.

You can also swap bedding between the two rooms, and use a plug-in pheromone diffuser in the main living areas to help everyone feel calmer.

Week Two: Sight Through a Barrier

Once both cats are eating comfortably near the door, crack it open just enough for them to see each other — a baby gate or a stack of two gates works brilliantly, as it allows visual contact without physical access. Keep these sessions short, no more than five to ten minutes, and always pair them with something pleasant: a meal, a bit of cooked chicken or a favourite wand toy.

• Watch for relaxed body language: soft ears, slow blinking, tails held loosely.
• End the session on a good note, before either cat becomes tense.
• Never punish a hiss or a swat. It is communication, not aggression, and telling a cat off will only make them more anxious.
• Give your older cat plenty of one-to-one attention so they don't feel displaced.

The First Supervised Meeting

When the barrier sessions are consistently calm, it's time for a proper introduction in a neutral room. Keep the kitten in a carrier or on a harness at first, or hold them securely, and let your older cat approach at their own pace. Have a towel handy in case you need to separate them calmly, and never pick up a cat mid-scuffle.

Keep the initial meeting to a few minutes. Then separate them again, even if all has gone well. Short, positive encounters repeated over days are far more effective than one long session. Gradually extend the time together as confidence grows, always with you present.

Hissing, a gentle swipe and the occasional stare are all normal. Genuine fighting — flattened ears, yowling, fur flying — means you have moved too fast and should return to the barrier stage for a few more days.

Building a Peaceful Home Together

Once the cats are sharing space, the focus shifts to managing the environment so both feel secure. Cats cope best when they have options, so make sure there are plenty of resources scattered around the home rather than grouped together.

• Provide multiple feeding stations, water bowls and litter trays in different rooms.
• Add vertical space — cat trees, window perches and shelves — so your older cat can retreat upwards when the kitten is being boisterous.
• Keep a couple of rooms kitten-free so the adult has somewhere quiet to nap.
• Schedule daily play sessions with the kitten to burn off energy, and separate calm cuddle time with your older cat.
• Use food puzzles and treats to create positive moments when the two are near each other.

Some cats become firm friends within a fortnight; others simply agree to share a sofa and ignore one another. Both outcomes are fine. What matters is that neither cat is hiding, over-grooming, refusing food or avoiding the litter tray. If you see any of those signs, slow down and speak to your vet, who can rule out health issues and may refer you to a feline behaviourist. With time, patience and a well-managed home, most pairs settle into a comfortable, if not always affectionate, arrangement.