September 17: Wild Worms

“I want my life to be a celebration of slowness...If we have open space then we have open time to breath, to dream, to dare, to play, to pray to move freely, so freely, in a world our minds have forgotten but our bodies remember."-Terry Tempest Williams, Red: Passion and Patience in the Desert

The garden compost bins, our place for worm scavenging

Monday, September 17:
earthworms and worm farms
(Sources:  My First Nature Book, How Earthworms Work, Camp Seymour "Wild Worms" Curriculum, Invasive Worms Video, Giant Earthworm Video)  

Materials: worms, soil, sand, mason jar, leaf litter, fruit, trowel, "earthworm" Powerpoint

Objective: Students will learn about worms who like fungi, act as decomposers.  Students will learn about worms, observe worms, and build a worm bin so they can continue to monitor their worms.

Class Introduction/Hook: Worm observation

Once again, we were a class with one teacher and one student, a tiny unit of science study.  M and I started class today by looking at a worm.  Earlier in the day, I'd dug red wigglers from the compost bin to ensure they'd be there in the afternoon during science class.  M and I watched the worm wriggle in my palm.  He pointed out that the worm could move both forward and backward.  I talked about the worm's individual body segments, explaining how they flex behind the setae.

M and I started our worm class, inside, with a Powerpoint I'd created.  I wanted to have time to sit and listen, question and converse before we got into the day's activity.

M and I talked about the size range of earthworms (on average between .4 inches and 9 feet.)  We measured out nine feet on the floor and watched a short video  about some of the world's largest earthworms.  We discussed the prevalence of earthworms (on average 500,000 to 2 million individual earthworms per hector) and the fact that earthworms are not native to most northern regions of the United States.  They traveled here on the roots of plants brought in by European settles.  We brainstormed positive and negative effects of bringing in such a pervasive species.

We acted out how a worm eats, pretending to be the mouth, crop, gizzard, intestines, and anus of an earthworm.  We made up dance motions and lines for each place food must be processed in order for an earthworm to digest it and talked about the low percent of nutrients (27%) that the worm retains and the high percent (73%) that gets returned to the soil.  We compared and contrasted worms with other decomposers.  We also talked about the way worms breath (through their skin) and the importance of the mucus layer that surrounds their skin to their respiration.  We talked about worms on the sidewalks and worms in the rain and discussed what conditions make a good habitat for worms.

M and I then went outside, a good habitat for both of us, to build a worm farm.  We walked to the compost bin where we sifted soil with our trowels.  M wondered if we would find any worms at all.  It took a while for the red wigglers to begin to surface.  Meanwhile we filled a Mason Jar with layers of sandy-soil and nutrient dense soil, to make a place for the worms to tunnel.  When we found red wigglers we put them in the jar.  We sifted and sang and talked about worms till we'd added nearly two dozen to our worm farm.  When M felt satisfied with the worms we found, he layered the top with leaf litter for the wigglers to feed on.  We headed back to school where we covered our worms in a piece of tool, and wrapped a sheet of black construction paper around our jar to give the worms darkness and privacy to begin tunneling through their new home. 

Litter horizon of our worm bin

Worm farm

Washington State Content Areas Covered:

EALR 4: Life Science 
Big Idea: Biological Evolution (LS3)
Core Content: Variation of Inherited Characteristics

Students know that:
-2-3 LS3A There are variations among the same kinds of plants and animals.
-2-3 LS3B The offspring of a plant or animal closely resembles its parents, but close inspection reveals differences
-2-3 LS3C Sometimes differences in characteristics give individual plants or animals an advantage in surviving and reproducing.

Students should be able to:
• Give examples of variations among individuals of the same kinds of plants and animals within a population (e.g., tall and short pine trees, black cats and white cats, people with blue eyes or brown eyes, with freckles or without).
• Compare the offspring of a plant or animal with its parents, listing features that are similar and that are different.

 • Predict how differences in characteristics might help one individual survive better than another (e.g., animals that are stronger or faster, plants or animals that blend into the background, plants that grow taller or that need less water to survive).