Earth Science Experiment: Learn How Worms Aerate Soil

Have you ever wondered why earthworms come out in the rain and dry up in the sun? It isn’t because they’re part vampire (we promise!), but because without moisture, they suffocate. See, earthworms don’t have lungs, and instead breathe through their skin. Air can’t dissolve on the worm’s skin without the help of moisture, which is why they produce that slimy mucus they’re so well-known for. Their mucus only goes so far, though, so they still need to stay out of the hot sun to keep breathing easy.

This is why a nice rainy day or dewy morning is the perfect opportunity for earthworms to enjoy some time on the surface, which in turn is great for worm-eating birds like robins. But worms aren’t just an important source of protein for our feathered friends, they also help plants grow! Do this fun experiment with your child to learn more about all the hard work worms do to contribute to the earth.

How hard do worms work to mix and aerate the soil? You can find out with this cool experiment! 

You will need:

A large glass jar or two-liter bottle with the top cut off*


Potting soil

Some dead leaves

Dark colored construction paper


Decorating materials

3-4 earthworms


*Note: Don’t put a lid on your jar or bottle or the worms won’t get enough air. They will burrow down and won’t try to escape!

  1. Your black construction paper is going to go around the outside of your worm hotel, so feel free to decorate it. We decorated ours with a Halloween theme.
    A black piece of construction paper that a child is decorating
  2. Put a layer of sand in the bottom of your jar or bottle, then alternate layers of soil and sand with some dead leaves mixed in for food. Don’t forget to use your water to dampen the layers as you go to help your little friends breathe! 
    Scooping dirt into a container
  3. Next, tape your construction paper around the bottle or jar so your worms will travel all around the jar (remember, worms avoid the sun, so make sure to seal all the moisture-sucking brightness out.)
    Decorated construction paper wrapped around a container.
  4. Once the layers are complete, add your earthworms to the top and watch them start to burrow down. After a few days, remove the construction paper and see how their movement has disturbed the layers of sand and soil. Pretty cool, huh?
    Mixed sand and dirt, a result of the worms' hard work

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