Physics activities can be absolutely hands-on and engaging for kids. Learn what capillary action is with our simple definition below. Plus, check out these fun science experiments demonstrating capillary action to try at home or in the classroom. As always, you’ll find fantastic and easy to do science experiments at the tip of your fingers.


capillary action activities for kids


Some of our most enjoyed science experiments have also been the simplest ones! Science doesn’t need to be complicated or expensive to set up, especially for our Junior Scientists.

Introduce new concepts like capillary action with fun, hands-on science experiments, and easy to understand definitions and science information. When it comes to science learning for kids, our motto is the simpler the better!

What Is Capillary Action?

In simple words, capillary action is the ability of a liquid to flow in narrow spaces without the help of an outside force, like gravity. 

Plants and trees couldn’t survive without capillary action. Think about how large tall trees are able to move a lot of water so far up to their leaves without a pump of any kind.

How Does Capillary Action Work?

Capillary action happens because of several forces at work. This includes the forces of adhesion (water molecules are attracted and stick to other substances), cohesion, and surface tension (water molecules like to stay close together).

When the adhesion to the walls is stronger than the cohesive forces between the water molecules water capillary action happens.

In plants, water travels through the roots and narrow tubes in the stem before moving to the leaves. As water evaporates from the leaves (called transpiration), it pulls more water up to replace what has been lost.

Also, learn about the surface tension of water!

Below you will find several great examples of capillary action at work, some using plants and some not.

What is the scientific method?

The scientific method is a process or method of research. A problem is identified, information about the problem is gathered, a hypothesis or question is formulated from the information, and the hypothesis is put to test with an experiment to prove or disprove its validity.  Sounds heavy…

What in the world does that mean?!? The scientific method should simply be used as a guide to help lead the process.

You don’t need to try and solve the world’s biggest science questions! The scientific method is all about studying and learning things right around you.

As kids develop practices that involve creating, gathering data evaluating, analyzing, and communicating, they can apply these critical thinking skills to any situation. To learn more about the scientific method and how to use it, click here.

Even though the scientific method feels like it is just for big kids…

This method can be used with kids of all ages! Have a casual conversation with younger kiddos or do a more formal notebook entry with older kiddos!

Click here to get your free printable science experiments pack!


Here are some fun ways to demonstrate capillary action. Plus, all you need is a handful of common household supplies. Let’s play with science today!

Celery Experiment

There’s nothing better than science in the kitchen! Set up a celery experiment with food coloring to show how water travels through a plant. Perfect for kids of all ages!

Celery Capillary Action

Color Changing Flowers

Grab some white flowers and watch them change color. We also did a green version of this experiment for St Patrick’s Day.

Color Changing Flowers

Coffee Filter Flowers

Explore the colorful world of science meets art with these coffee filter flowers. Here’s an alternative way to make coffee filter flowers too!

Coffee Filter Flowers

Leaf Veins

Collect some fresh leaves and observe over a week how water travels through the leaf veins.

How Do Leaves Drink Water?

Toothpick Stars

Here’s a great example of capillary action that doesn’t use plants. Make a star out of broken toothpicks by only adding water.  It all happens because of the forces in capillary action.

Toothpick Stars

Walking Water

This colorful and easy-to-set-up science experiment moves water through paper towels via capillary action.

Walking Water


The uptake of water in paper using markers is a fun and simple way to explore an example of capillary action.

Walking Water


Click on the image below or on the link for tons more cool kids science experiments.