Science experiments are the perfect kind of messy fun. Preschoolers get the thrill of colours changing, bubbles popping and fizzy reactions happening right in front of them — and parents get all the learning that comes packed in alongside the mess.
Get started with these easy science experiments, perfect for preschoolers and toddlers alike. Most use everyday ingredients you’ll already have at home, and many are simple enough that older siblings will happily join in too, making them a lovely family activity for a rainy afternoon or a free weekend.
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Easy Science Experiments for Preschoolers
#1. Ice and Salt Experiment
Image: Learning & Exploring Through Play
This salt and ice experiment is genuinely fascinating to watch — for grown-ups as much as toddlers. As the salt melts little craters into the ice, food colouring seeps through and creates beautiful coloured tunnels right before your eyes.
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#2. Colour Mixing on Coffee Filters
Image: Messy Little Monster
Using primary colours (red, yellow and blue) and coffee filters, let your child explore all the secondary colours they can create. It’s fascinating to watch the paint spread and soak into the filter. Messy Little Monster uses jumbo eye droppers for this simple colour mixing activity, which is also great for building fine motor skills.
#3. Make Glow in the Dark Bubbles
Make your very own glow in the dark bubbles for hours of outdoor fun once it gets dark.
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#4. Pop Rock Balloons
Image: A Little Pinch of Perfect
This is a great idea from A Little Pinch of Perfect for pop rock balloons. As the Pop Rocks meet the soda, tiny bubbles form — and as they pop, the trapped air fills the balloon right in front of your child’s eyes.
#5. Create Fizzy Lemonade
Image: Learn with Play at Home
Let your preschooler create their own edible science experiment. This fizzing lemonade experiment from Learn With Play at Home is a fun one to try just before mealtime.
#6. Simple Colour Mixing Science
Image: My Mundane and Miraculous Life
Simple, fun and educational — sometimes the easiest set-ups are enjoyed the most. Most preschoolers love water play, and this easy colour mixing science experiment from My Mundane and Miraculous Life is sure to be a hit. Just add food colouring and let them create their own colours.
#7. Little Scientist Space
Image: Epic Childhood
If you’d like to set up a space that invites lots of experimenting and imaginative play, Epic Childhood shares some lovely ideas for little scientists in this post, including how they set theirs up.
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#8. Colourful Milk Experiment
Image: Crafts by Amanda
This colourful milk experiment from Crafts by Amanda needs just milk, food colouring and dish soap. There’s a helpful video to follow along with, plus a simple explanation of the science behind the fun.
#9. Walking Water
Image: Parenting Chaos
This colour-mixing activity is a real showstopper — a beautiful rainbow experiment using walking water from Parenting Chaos. With just a few simple tools, little ones can watch in amazement as new colours appear before their eyes.
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#10. Water Bottle Fountain
Image: Learn with Play at Home
Add a twist to water play with your very own fountain. This water bottle fountain experiment from Learn with Play at Home helps children see that air takes up space and is always present, even though we can’t see it.
#11. Oil and Water Discovery Bottles
Image: Play Trains
Children this age love transferring, filling and emptying containers. Add a couple of simple ingredients and you can extend that play by letting them explore what happens when you combine oil and water. Get the full instructions over at Play Trains.
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#12. Rainbow Eruptions
Image: Learn Play Imagine
These rainbow eruptions from Learn Play Imagine look absolutely beautiful — and need just two simple ingredients to recreate at home.
#13. Fireworks in a Jar
Image: I Can Teach My Child
If your little one is fascinated by colours and fireworks, this fireworks in a jar project from I Can Teach My Child is for you. The best part is you’ll likely already have everything you need at home.
#14. Colouring Flowers and Vegetables
There are so many lovely variations of this classic experiment. Here’s a handful of our favourites:
- Colouring Wild Carrot – Fireflies and Mudpies
- Colouring Roses – Hello, Wonderful
- How Does a Plant Drink? – Science Foundation Ireland
- Dye One Flower Two Colours – Homegrown Friends
#15. Soap Clouds
Image: Our Best Bites
Soap clouds, like these from Our Best Bites, smell wonderful and are great for sensory play. Children love standing and watching the “cloud” form. Get the full details at Our Best Bites.
#16. Rainbow Paper
Image: The Science Kiddo
This rainbow paper is so effective, and takes just five minutes to make. Find the project and instructions at The Science Kiddo.
#17. Sink or Float
Image: The Joys of Boys
All you need is a container of water and a hunt around the house for objects to test. Enjoy this sink or float experiment from The Joys of Boys, taking turns to predict whether each item will sink or float — a great way to build early mathematical thinking too.
#18. Cress Heads
This cress heads experiment teaches children what plants need to grow, and cress is perfect for little ones because it grows so quickly.
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Stop by Learning and Exploring Through Play for lots more ideas for activities for little learners.
Frequently Asked Questions
What age are these science experiments suitable for?
These experiments are designed with preschoolers in mind, but most work well for toddlers with a little extra supervision and are just as enjoyable for older siblings, making them a good pick for mixed-age family activities.
Do I need special equipment to try these experiments?
No — nearly all of these use simple household ingredients like food colouring, water, milk, oil, salt and everyday containers. Each experiment links through to the original creator’s blog for the full ingredient list and step-by-step instructions.
Are these experiments messy?
Some are, by design! Water, colouring and soap feature heavily, so it’s worth doing several of these outdoors, over a tray, or with old clothes on.
Can these experiments help with early learning skills?
Yes. Alongside the fun, many of these experiments quietly build fine motor skills, early scientific thinking, colour recognition and vocabulary around cause and effect.
Related Articles
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- 27 Innovative Water Play Ideas for Kids
- 28 Rainbow Inspired Activities for Kids
- Tips for Making Gardening Fun for Kids
Save These Ideas for Later
Love these experiments? Bookmark this page or save it to your favourite parenting board so you’ve always got a new one to try on a rainy day or during the school holidays.
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