Lesson plan

Decomposers with a focus on worms

Look for animals outside, or in soil brought into the classroom. Discuss the role of decomposers in the food chain. Then look closely at red wiggler worms, or other small garden worms, before using them to start an indoor worm compost bin.
Science content
Biology: Features, Adaptations of Living Things (K, 1, 3, 7)
Biology: Classification of Living Things, Biodiversity (1, 3)
Biology: Life Cycles (2)
Biology: Food Webs, Ecosystems, Biomes (3, 4)

Either start the lesson with a walk outside to find worms and other animals in the soil: decomposer hunt activity.
Or look for animals in soil brought into the classroom: soil habitat study activity.
Discuss how these decomposers are critical to the food chain, as they eat dead plant and animal matter and turn them into rich soil, containing simpler nutrients to be used by plants and other organisms.
(Or just start with the discussion.)

Then look at one of these decomposers, worms, more closely: Observe worms closely (including any found outdoors).

End by setting up a habitat for decomposers in the classroom:Set up worm bin. Optional: add other decomposers, e.g. wood bugs, to it.

Optional: visit school compost bin outside.


At the New York After School Program (The School at Columbia), students just looked into an already established worm compost rather than building their own. They looked at worms closely, then fed the worms in the compost bin.

Grades taught
Gr K
Gr 1
Gr 2
Gr 3
Gr 4
Gr 6