Worm science P–2

https://wasteauthority.wa.gov.au/wws/curriculum-materials/detail/worm-science-p2

Created Date:
Thu 29 October 2020

Last Edit Date:
Mon 13 February 2023

Students look at worm features and adaptations that help them to survive.

Learning objective

Students describe how a worm moves, how this depends on their size and shape, and share their worm observations with the class. They discuss where worms live and why they live there. Students observe worms at different stages of life, draw a worm and label the head and saddle. Students measure a worm using informal methods.

Curriculum links

Science: Science understanding

Biological sciences

Science: Science inquiry skills

Questioning and predicting
Planning and conducting

Cross-curriculum priority: Sustainability

General capabilities

  • Literacy
  • Numeracy
  • Ethical understanding
  • Critical and creative thinking
  • Personal and social capability

Key concepts

Adaptations, behaviours, body coverings, body parts, survival

Background information

Worm farms contain composting worms that eat food scraps and turn them into a natural liquid (worm leachate) and compost (castings) that can be used in the garden. Composting worms thrive in a moist, high nutrient environment and we create this environment in a worm farm.

Worm farms:

  • Decrease the amount of organic waste sent to landfill.
  • Close the recycling loop by changing food waste back into organic fertiliser for growing food.
  • reduce greenhouse gases. In a well-maintained worm farm the decomposition process is aerobic (with oxygen), rather than anaerobic (without oxygen).

The earthworms used in worm farms are a different species to those we find in our garden. The best worms for worm farming are European worms such as the red wriggler (lumbricus rubellis) and the tiger worm (eisenia fetida). These species are accustomed to soils high in nutrients. They eat and breed much faster than other earthworms and can quickly transform food scraps into worm castings. They do this in a small amount of space, while other earthworms are better equipped for burrowing and searching for food in our drier, nutrient poor soils.

Worms are blind, but sensitive to light. Their instinct is to move away from light due to their two ‘photoreceptors’, which are sensitive nerve endings located near the saddle (Murphy, 2005).

Worms have three to five hearts depending on the species and breathe through their skin. We can identify its ‘head’ as it is the end closest to the saddle (clitellum), a band around the worm. It moves through the soil by contracting and expanding its muscles and using its bristles (setae) to grip the soil.

Resources required

A few handfuls of worms and castings from your worm farm, including some juvenile worms and capsules

Water

One plastic lid per pair (white ice cream container lids are ideal)

Magnifying glasses or magnifying cups

Science journal

Worm diagram

Activity

  1. Discuss features of a worm (saddle, segments, and head) by showing the worm diagram.
  2. Before distributing live worms, explain to students that the worms must be treated gently and touched as little as possible.
  3. Give each pair one worm to look at. Place it on the plastic container lid with a drop of water to keep the worm moist.
  4. Using a magnifying glass and working in pairs, students observe and draw a picture of a live worm. Highlight some of the features discussed in the beginning of the lesson.
  5. Ask students to label the saddle and head on their worm drawing.
  6. Place worms back into the worm farm after examining them.
  7. Students compare their drawings and observations.
    As a class:
    • ask students how they know worms are living things
    • discuss how worms move and why
    • mime the movement of a worm.
  8. Discuss what students have learned about worms and why they have certain features that help them to survive.

Taking it further

Create a class table for recording the measurements of the worms.

For more lessons related to worms, please view the waste wise schools worms    curriculum guide www.wasteauthority.wa.gov.au/wws/teaching-resources/list/curriculum_guide

Useful resources

‘Waste wise worm farming’ and ‘How to make a fridge worm farm’ fact sheets: www.wasteauthority.wa.gov.au/wws/teaching-resources/list/fact-sheets

Costa’s guide to worm farming and composting for households:

www.youtube.com/watch?v=eNqRXM2c6L8