Worms don't just push their way through the soil, they eat their way through,  In a single day an earthworm gobbles up more than its own weight in dirt, sand, bits of leaves and grass, and almost anything else that happens to be in its way as it burrows from one place to another.  By the time the stuff comes out its other end, it has been ground up and mixed with the worm's own body fluids and is a perfect food for plants.  That's why gardeners are always so happy to find earthworms in their garden.)

What You'll Need:

*quart jar (or larger)
*sand
*dark garden soil
*trowel
*worms
*rotted leaves or compost
*spray bottle of water
*black construction paper
*cellophane tape
*scissors
*squeeze-on plastic fabric paints

What To Do:

 1.  Place a layer of sand around  1.5  in. deep in the jar.                                                                                                           2.  Place a layer of soil about the same depth on top of the sand.
 3.  Continue alternating layers of sand and soil, smoothing each layer as you go.
 4.  Add 3-4 earthworms to the top layer of soil.
 5.  Cover with a layer of  rotted leaves or compost.
 6.  Spray the top layer with water, lightly.
 7.  Cut black paper to fit around jar.
 8.  Put a strip of tape down one short edge.
 9.  Decorate the paper with plastic paint.
10.  Wrap the paper around the jar.  Make a tab of tape that is attached to the paper on the end that doesn't have the strip of    tape.  You can stick/unstick the tape tab to the shiny cellophane tape strip.
11.  Untape the tab after a few days and remove the paper to see what the worms have done to the layers of sand and soil.  Make a drawing of their tunnels every few days to record their actions.