Cat behaviour
Introducing cats to each other
Slow and steady wins. Cats are territorial, and a new cat is a big change. Give them time — weeks, months, sometimes up to a year — and don't be discouraged by setbacks.
Before you start: be patient with yourself too
- There's no deadline. Some cats are friends in two weeks. For many it takes two to three months, and for some it takes six months to a year.
- Going backwards is part of it. Nearly every introduction has bad days — they don't erase the progress you've made.
- Slow is fast. Rushing one stage is the most common reason introductions have to start over. Taking an extra week now can save months later.
- Peaceful tolerance is a success. Not every pair will cuddle. Cats who share a home calmly, without stress, are a happy ending.
- Every calm meal near the screen and every slow blink is a step forward. Celebrate the small wins.
- You're doing something kind. Taking it slowly shows both cats that their home is still safe.
The five stages
Move on only when both cats are relaxed — let the cats set the pace, not the calendar.
The new cat settles in a safe room of their own. The cats can't see each other — they only learn that the other exists.
- 1Set up a spare room or bathroom with food, water, litter box, a bed, scratching post, hiding spots and toys — everything the new cat needs, far apart from each other.
- 2Keep the door closed. A towel along the bottom gap stops paws reaching under.
- 3Plug a Feliway Classic diffuser into this room, and a Feliway Optimum or Friends diffuser in the main living area, 24–48 hours before the new cat arrives if you can.
- 4Spend calm time with both cats separately, so your resident cat doesn't feel replaced. Keep their routine exactly the same.
- 5Feed both cats on either side of the closed door, starting far from it.
Ready for the next stage when
- The new cat eats, uses the litter box and explores their room confidently.
- Neither cat is hissing or growling at the door.
Reading their body language
Going well — keep going
- Slow blinking at each other
- Relaxed, upright or gently curved tail
- Ignoring each other
- Eating, grooming or playing with the other cat in view
- Sniffing noses, then walking away calmly
- Lying down with belly or side showing
Too fast — step back a stage
- Hissing, growling or spitting
- Flattened ears, dilated pupils
- Puffed-up fur or a lashing, thumping tail
- Hard staring or stalking
- Hiding for long periods, not eating
- Peeing or pooping outside the litter box
Helpful tools
Mesh screen or tall baby gate
Lets the cats see and smell each other with zero risk of a fight. A screen door, two stacked baby gates or a pet gate with a cat door that locks all work.
Feliway (pheromone diffusers)
Feliway Classic copies the 'this place is safe' cheek pheromone — good in the new cat's room. Feliway Optimum or Friends copies the mother-cat pheromone that helps cats get along — good in shared rooms. Plug in 1–2 days before and keep running for at least a month. They help, but don't replace a slow introduction.
Wand and feather toys
Play is the best distraction. A wand toy lets you play with a cat from a distance, so they focus on the toy, not the other cat. End each session with a treat, like a 'catch'.
Puzzle feeders and lick mats
Keep cats busy and calm during barrier sessions. Licking is naturally soothing.
Extra litter boxes, bowls and beds
One per cat plus one, spread out. Competition over resources is one of the most common reasons introductions fail.
Cat trees and wall shelves
Height lets a nervous cat watch from safety and gives a confident cat their own place. More vertical space means less conflict.
Hiding spots
Boxes, covered beds and tunnels. A cat who can hide feels safe enough to come out.
Tasty high-value treats
Lickable treats, small pieces of cooked chicken or freeze-dried treats — saved only for introduction sessions, so the other cat means 'something great happens'.
If things go wrong
- •Don't punish, shout or spray water — it makes the cats link each other with fear.
- •If a fight starts, interrupt with a loud clap or by sliding a cushion or board between them. Never use your hands.
- •Separate them calmly, let both cats calm down for a few hours, and check for wounds.
- •Go back one or two stages and move slower. This is completely normal, not failure.
- •Re-introduce scent swapping after any time apart, even a vet trip — a cat that comes home smelling of the clinic can be 'a stranger' again.
- •Book a vet check if one cat suddenly becomes aggressive — pain or illness is a common hidden cause.
- •If there's no progress after several months, ask your vet about a feline behaviourist, and in some cases calming medication.