science activity for kids
The Very Hungry Caterpillar Science Experiment
If you’re looking for a science experiment that stops kids in their tracks, makes them gasp, and immediately ask “can we do it again?” – this is it.
This fizzing Hungry Caterpillar science experiment takes the classic baking soda and vinegar reaction and turns it into an adorable, story-inspired sensory moment your preschool or kindergarten class will be talking about all week.
The setup is simple: mini cups arranged in a caterpillar shape on a tray, filled with vinegar and food coloring, with a sprinkle of baking soda that sets off a fizzing, bubbling reaction right before their eyes.
It’s process art, science, and Eric Carle magic all in one activity – and it requires very little prep for a science experiment.
Whether you’re using it as a companion activity to the book, a spring science center, or just a Friday fun experiment, this one delivers every single time.
Watch the video tutorial below.
Why Kids Love This Fizzing Hungry Caterpillar Science Experiment
Let’s be real – the baking soda and vinegar reaction is a classic for a reason. Kids never get tired of the fizz.
But what makes this version extra special is the visual setup. The moment students see a tray of cups arranged in the shape of a caterpillar – with googly eyes and little pipe cleaner antennae on the head…
They are completely hooked before the experiment even begins!
Then when the baking soda hits the vinegar and the red head starts bubbling and the green body segments all start fizzing at once, the reaction in the room is just as good as the reaction in the cups.
It’s the kind of moment that makes kids feel like scientists – because they are.
purpose
Explore cause and effect
Safe way to observe chemical reactions
Fun way to introduce the scientific method
Fun Hungry Caterpillar book extension activity
Safety Tips & Teacher Notes
Because this experiment creates a bubbly, fizzy reaction, a few simple safety steps will help keep the experience fun and stress-free for everyone.
Use a Tray: Do this experiment on a tray with raised edges – the fizzing reaction can overflow the cups and things get wonderfully messy.
Look Don’t Touch: Remind students not to touch their eyes during or after the experiment, especially with food-coloring-stained fingers.
Open a Window: White vinegar is safe and non-toxic but smells strong in an enclosed space – near a window or outdoors works great if possible.
Adult Supervision: For younger preschoolers, teacher-led is best. Kindergartners can often manage their own baking soda scoop with a little guidance.
Paper towels: Have paper towels or a drop cloth ready. This is a happy mess – just plan for it.
directions
How to do the Fizzing Hungry
Caterpillar Science Experiment
Set cups on a tray in caterpillar formation
Add googly eyes and an antenna to the first cup
Fill the cups 3/4 full with vinegar
Add red food coloring to the first cup
Add green food coloring to the remainder of cups
Add 2 tablespoons of baking soda to each cup
Watch the reaction!
Continue adding baking soda until the reaction stops
The Science Behind the Fizzing Hungry Caterpillar Experiment
What your students just witnessed is a classic acid-base chemical reaction.
Vinegar is an acid and baking soda is a base
When the two mix, they react and produce carbon dioxide gas.
Carbon dioxide gas is what creates all those wonderful bubbles and fizzing.
For preschool and kindergarten, you don’t need to go deeper than “the vinegar and baking soda are mixing and making bubbles of gas!”
But older kindergartners love hearing the words “chemical reaction” and feeling like real scientists. Use whatever language fits your class.
The food coloring doesn’t change the reaction at all – it just makes it way more fun to watch. Which is honestly a perfectly valid scientific reason to include it.
Extension Ideas for Little Learners
There are so many simple ways to keep the learning going without adding extra prep with this science experiment. These extension ideas help reinforce early math, language, and observation skills while keeping the Caterpillar excitement alive.
Read The Very Hungry Caterpillar aloud before the experiment and have students predict what will happen when the caterpillar eats something fizzy.
Follow up with a caterpillar life cycle craft using paper circles or egg cartons.
Try a color mixing extension – what happens when you mix the red and green vinegar together?
Head outside for a real caterpillar hunt and record observations in a nature journal.
