The Cheerios Effect.

You can make Cheerios attract each other like magnets. It’s called “The Cheerios Effect.”


  • Bowl
  • Water
  • 1 cup of Cheerios, or other light breakfast cereal, like Kix
    English: A bowl of Cheerios

    A bowl of Cheerios (Photo credit: Wikipedia)


  • Half a dozen paper clips
  • 1 Tablespoon of dishwashing liquid
  • 3 toothpicks


  • Fill bowl with water
  • Drop one Cheerio at a time into the water, until you have at least a dozen
  • Unfold half of a paperclip at right angles to the rest of the clip
  • Lay a flat paperclip on top of the flat portion of the opened-up clip
  • Lower the flat,, unfolded section of the paperclip, with the flat, unbent paperclip on top of it, gently into the water so it floats
  • Dip a toothpick into the dishwashing liquid
  • Dip the toothpick into the water near, but not touching the paperclips and Cheerios

What Should Happen:

As you continue to drop the Cheerios into the water, you will notice them start to float toward each other. They will make small rafts of Cheerios, clinging to each other.

The paperclips will also start to float toward each other.

Both paperclips and Cheerios will also seek out the sides of the bowl.

When you dip the dishwashing liquid-tipped toothpick into the water near the Cheerios and paperclips, they will scoot away from the toothpick.

Eventually, they will sink.

Why Is This Happening?

Surface tension creates a film of milk that allows objects that would otherwise sink to stay on top of the milk.

Surface tension is caused by the fact that liquid molecules act differently with each other than with air molecules.

Where they meet, at the surface of the milk, the liquid can support objects that are lowered onto it gently.

But, each object bends, or dips, the surface a little.

That is why, as the objects float near each other, they appear to be attracted, as though they were magnets.

The same effect, or bending, is true at the edges of the bowl.

Soap disrupts the surface tension of the liquid. When soap is added to the water near an object that is floating, it sinks.

Click here to see a YouTube video of this activity.

When I did this with my grandson, it worked as expected, except I had to hurry to put Cheerios into the bowl before he ate them all!

Click here for an explanation of the Cheerios effect. Thanks to for this activity.


Carol Covin, Granny-Guru

Author, “Who Gets to Name Grandma? The Wisdom of Mothers and Grandmothers

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