Kitten Development Stages

No two kittens grow the same way, but they all follow common kitten development stages, a path starting with eyes shut and ears still closed, and ending with confident leaps onto your kitchen counter, sofas, and curtains. 

Knowing what happens between those two points in kitten development makes life easier for both of you. It tells you when to expect the first stumble out of the nest, when to switch up food, and answers usual questions like “when do kittens start walking?” or how soon they should be using a litter tray.

These kitten stages shape how your kitten learns to trust, play, explore, and interact. Some moments come quickly; others take a bit of patience. But once you understand what’s going on beneath all the fluff and twitchy whiskers, it’s much easier to respond with the right kind of care. That could mean moving a litter tray to the right spot, knowing when to hold back, or simply noticing when a new behaviour is perfectly normal and when it might need a closer look. 

In raising a kitten, you’re slowly learning their language as they grow, one phase at a time.

The Newborn Kitten

At birth, kittens have their eyes shut, ears folded, bodies soft and small. They can’t see or hear, and their movements are more reflex than intent. They rely entirely on their mums to stay warm, fed, and clean. Without them, they can’t even go to the toilet. 

If the mothers are there during these kitten stages, your job is mostly to keep the space warm and quiet, and check that each kitten is feeding and gaining weight. If they’re not, the work is constant: hand feeding every couple of hours, keeping their body temperature stable, and gently helping them urinate and defecate.

It’s a quiet stretch of life, mostly sleeping and feeding, but it matters more than it looks. A warm, well-fed kitten at this stage is off to a strong start of their kitten development.

1 – 3 Weeks: Kittens Open Their Eyes and Ears

Somewhere around the end of the first week, kittens begin to open their eyes. Their eyes will look a little cloudy at first and often appear blue, regardless of what colour they’ll settle into later. By the time they’re two to three weeks old, baby teeth start to erupt, their ears uncurl and lift, and they begin responding to sound.

In earlier kitten stages, they’ve relied on touch and smell. But once they can see movement and hear noise, this marks one of the essential kitten development stages, as they start responding to things around them. They may turn towards your voice or twitch at sudden sounds. They also begin to recognise the shape and sound of their littermates, their mum, and anyone who regularly handles them. 

Around this time, many owners start wondering “when do kittens start walking?”, as their movements become more purposeful, though still unsteady. This is the point where you’ll start to see little signs of curiosity: sniffing at a hand, trying to wobble towards a new texture, reacting to a toy with their paw.

It’s a good time to start laying the base for trust and social comfort:

• Begin gentle handling for a few minutes each day to help kittens get used to human touch.
• Keep movements slow and voices soft; this helps build trust early on.
• Make sure the space stays warm and free from sudden noises or changes.
• Avoid overstimulation. Short, calm interactions are best at this stage.
• Monitor their responses. Some kittens take to handling faster than others, and that’s fine.

3 – 5 Weeks: Walking and Using the Litter Box

Between three and five weeks, kittens enter one of the most important kitten development stages, shifting from wriggly little bundles to wobbly explorers.

Their limbs start to catch up with their instincts, and you’ll see them standing more confidently, taking shaky steps that quickly turn into determined, if clumsy, walking. By four weeks, most kittens can manage a slow trot, and by five, they’re often seen running short distances, wrestling with their siblings, and practising tiny leaps.

Alongside this newfound mobility comes the start of proper toileting habits. Around the three-week mark, kittens begin to gain control over their bladder and bowels. Up to this point, they’ve relied on their mother’s stimulation. They’re also more social now, approaching people on their own, playing with objects, and showing interest in their surroundings. 

As their coordination improves and they begin exploring more confidently, it’s the right moment to support their growing independence:

• Introduce a shallow litter tray with non-clumping litter, which is safe for curious mouths.
• Place kittens in the tray after naps and meals to encourage a toileting routine.
• Keep the tray close to their nest at first, then gradually move it as they become more mobile.
• Continue short, gentle handling sessions to build trust.
• Offer safe toys to help develop coordination and encourage play.

This phase of kitten development builds confidence both physically and socially, shaping habits they'll carry into adulthood. This is when personality starts to show, marking one of the most engaging kitten stages as boundaries begin to be tested.

6 – 8 Weeks: Socialising and First Vaccines

At this age, kittens reach one of the liveliest kitten development stages, turning up everywhere: under furniture, halfway up the curtains, and tumbling over each other in bursts of energy.

By 6-8 weeks, all 26 of their baby teeth are in place, their balance is better, and they’re bold enough to start exploring whatever’s in front of them. It’s through this kind of rough-and-tumble play that they figure out what’s too hard, too fast, or just enough.

But this part of the journey through kitten development stages is also when early habits settle in. Kittens who are gently handled now, who hear the hoover in the distance or get used to hands picking them up, are more likely to grow into cats who take things in stride later.

It’s also when their natural protection from mum’s milk wears off, which means it’s time to get them booked in for their first vaccinations.

Some useful things to keep in mind during this stage:

• Handle them a little every day, no rush, just soft hands, and calm voices.
• Let them meet a few people, slowly, so they don’t get spooked by strangers later.
• Offer different toys and spaces so they learn the world isn’t just one room.
• Book their first vet check, where they’ll start their vaccination plan.
• Discuss microchipping at these early visits, as it’s legally required for cats in the UK
• Get the vet’s advice on flea and worm treatments if that hasn’t been sorted already.

9 – 12 Weeks: Weaning and Learning Cat Skills

By this point, kittens are well on their way to being fully independent. The weaning process is usually finished or nearly there, most kittens will eat solid food at this point, though a few may still sneak the odd comfort feed from mums if allowed. Their meals now should be tailored to kitten needs: energy-dense, easy to digest, and offered in small, regular portions to suit their fast-growing bodies. You can explore a range of trusted kitten-feeding products to support them.

At the same time, they’re soaking up all sorts of lessons, mostly through play. Wrestling with siblings teaches them when to hold back, how hard to bite, and what’s too much. Scratching posts are there to help with claw health, mark territory, and release energy. And toilet habits should be second nature now, with litter tray use becoming automatic.

This is a stage where you’ll start to see clearer personality traits. Some kittens are bold and noisy, others more cautious. Either way, they’re watching everything: your routines, your tone, how you handle them. It’s a good time to set gentle boundaries and reinforce good habits.

A few things to focus on during this phase:

• Feed a high-quality kitten diet, little and often.
• Make sure scratching posts are accessible and sturdy.
• Stick to a consistent litter tray setup to reinforce the routine.
• Keep play structured but varied; let them chase, jump, stalk, and pounce.
• Focus on reinforcing gentle behaviour, and disengage to withhold attention if the cat resorts to rough biting or scratching.

3 – 6 Months: Ready for Adoption and Neutering

At this point, kittens have most of the basics down. They’re eating solid food, using the litter tray, and are more than capable of making their needs known. If they’ve stayed with their mum and littermates this long, they’ve likely picked up some good habits, learned how hard to bite, when to back off, and how to share space without chaos. That extra time matters, especially when it comes to social behaviour.

By now, they’re also the right age for adoption. Settling into a new home at this stage tends to go smoothly. They’re still young enough to bond quickly, but not so small that they need constant hands-on care.

This is also when your vet will talk to you about neutering. Some kittens hit puberty earlier than others, and it can happen sooner than expected. To stay ahead of it, spaying or castrating around five to six months is often the plan.

Here’s what to keep in mind around this stage:

• Check that they’re fully vaccinated before moving to a new home.
• Book in their spay or neuter procedure; your vet will give you a clear timeline.
• Keep worming and flea treatment regular.
• Reinforce the good habits already forming.
• Don’t stop playing. Daily movement keeps them sharp and settled. And as their appetite grows, you might want to double-check how often to feed a kitten to keep pace with their needs.
• Make sure you’re offering the right nutrition; read up on what to feed kittens to support healthy growth.

One Year: No Longer a Kitten

By the time a cat hits twelve months, they’re no longer classed as a kitten, even if they still race around the house at midnight. Physically, most have reached their full size, though some breeds continue to grow a little longer. The baby teeth are gone, the adult coat is in, and the manic energy of the earlier months starts to even out.

That said, some still carry a bit of that wild streak. This “young adult” phase is often a mix of growing confidence and the last of the teenage boundary-pushing. You might see calmer behaviour overall, more predictable routines, and a stronger sense of independence.

Around this point, it’s safe to switch to adult food, book a check-up if you haven’t already, and settle into long-term routines: feeding, grooming, and play. The whirlwind of early kitten development stages is done, but the best bit, the long stretch of companionship, has just begun.

Kitten Development Stages FAQs

When do kittens start walking?

At around three weeks, most kittens begin to stand and stagger a little. It’s not graceful, more of a wobble than a walk, but it’s the first sign of progress. Their muscles are still developing, and balance takes a while to click into place. This is typically “When do kittens start walking?” becomes a fair question, as they begin exploring their surroundings. By four weeks, they’re usually making short, clumsy journeys on their feet. A few might take longer, but by five weeks, most are confidently on the move.

What is the hardest age for a kitten?

The trickiest of kitten stages is between four and six months. By then, kittens are confident, fast, and into everything, but not quite old enough to know when to stop. They test boundaries, ignore earlier training, and seem to have endless energy.

It’s a time of physical growth and teenage-style behaviour, with some pushback against rules you thought were understood. For their people, it can feel like a constant loop of redirecting and repeating. Patience helps. So does play. This stage passes, but while it lasts, it keeps you on your toes.

What age are kittens the naughtiest?

Most kittens are at their most full-on between three and five months. Their brains are developing fast, especially the parts that control movement and curiosity. They’re wired to explore, but they don’t know the rules yet, so they climb what they shouldn’t, bite things that move, and knock over whatever’s in reach. It’s how they learn. 

The chaos of kitten development isn’t random, though. It’s part of how their body and brain sync up. A bit of structure now goes a long way later.