Understanding the Changes That Can Affect a Toddler’s Behaviour

Toddlers are incredible little humans curious, expressive, and constantly learning how the world works. But they’re also navigating huge developmental leaps and emotional waves that can make their behaviour change from one day to the next. As parents, it can feel confusing or overwhelming when your once calm child suddenly becomes clingy, irritable, or defiant. The truth is, toddler behaviour is deeply influenced by the changes happening both inside and around them.

Let’s explore the most common changes that can affect a toddler’s behaviour and how you can gently support them through each stage.

1. Developmental Milestones and Growth Spurts

Toddlers experience rapid brain and body development. New skills like talking, walking, or problem-solving can be exciting, but also overstimulating.

How it affects behaviour:

Increased frustration or tantrums

Mood swings

Changes in sleep

Clinginess or needing extra reassurance

Why: Their brain is working overtime, and they may struggle to communicate their needs clearly.

2. Shifts in Routine

Toddlers feel safest with consistency. Any disruption can feel huge to them, even if it’s small to us.

Common routine changes include:

Starting nursery or childcare

A new sibling

Parents returning to work

Changes in nap schedules

Moving house

Behavioural signs:

Regression (e.g., sleep, toileting, language)

Separation anxiety

Refusal to participate in normal activities

3. Emotional Development

Toddlers are learning to identify emotions but don’t yet have the tools to regulate them.

This might look like:

Sudden tears

hitting, biting, or pushing

Saying “no” constantly

Hiding, clinging, or refusing

They’re not being "naughty" they’re overwhelmed.

4. Sensory Changes and Overload

A new environment, loud noises, or too many activities can overwhelm sensitive toddlers.

Signs include:

Covering ears

Avoiding certain textures or foods

Running away or melting down

Becoming extra tired or irritable

Their behaviour is often a communication of discomfort.

5. Changes in Sleep or Appetite

Sleep regressions, growth spurts, or changes in diet all influence mood and behaviour.

For example:

A tired toddler may seem hyper or emotional

A hungry toddler may be cranky or aggressive

Many parents notice a direct link between sleep quality and behaviour the next day.

6. Social and Environmental Changes

As toddlers start interacting more with others, social expectations grow too.

Changes such as:

New caregivers

Interactions with other toddlers

Visiting new environments

Family stress or tension

Toddlers can absorb the emotional atmosphere around them, even if they can’t express it.

7. Teething and Physical Discomfort

Even in toddlerhood, molars and canines can cause pain.

This can lead to:

Restless sleep

Whining

Chewing on objects

Irritability

It’s hard for them to behave calmly when something physically hurts.

8. The Desire for Independence

Toddlerhood is the beginning of “I do it!”

They want freedom but also still need you.

Clashes happen when:

You step in to help

They can’t do something on their own

They don’t have the words to explain their frustration

This internal conflict often shows up as defiance or tantrums.

How You Can Support Your Toddler

Stay patient and consistent they thrive on stability.

Narrate emotions: “I see you’re frustrated because the toy won’t work.”

Prepare them for changes with simple explanations.

Offer choices to increase independence.

Prioritise connection even 10 minutes of focused play helps.

Keep routines predictable wherever possible.

Remember: behaviour is communication. Toddlers aren’t trying to give us a hard time they’re having a hard time.

Every toddler will go through periods of change that influence how they behave. These shifts aren’t signs of bad behaviour, poor parenting, or anything you’re doing wrong. They’re simply part of growing up. By understanding what’s going on beneath the surface, you can approach each phase with empathy, patience, and confidence.

You’re doing an amazing job

more than you know.