Summary Students each have a worm to observe closely Science content Biology: Features, Adaptations of Living Things (K, 1, 3, 7) Biology: Classification of Living Things, Biodiversity (1, 3) Biology: Food Webs, Ecosystems, Biomes (3, 4) Biology: Sensing, Organ Systems (4, 5, 6) Earth/Space: Sustainable practices, Interconnectedness (2, 5, 7) Science competencies (+ questioning + manipulation + others that are in every activity) Processing/analyzing: experiencing and interpreting the local environment (K up) Lessons activity is in Features and Needs of living things (animals) Decomposers with a focus on worms Plants interacting with animals Food chains Animal dung and the food web Carbon exchange between living things and the air Biodiversity Invertebrates Materials Worms e.g. red wiggler or small worm from the garden (or purchased), one per student Small petri dishes, one per student, with a film of water in each Magnifiers as many as possible Paper and pencil for drawing worm Image of worm (earthworm OK) showing insides of worm Procedure Before handing out the worms. practice using magnifier; look at the lines on your finger. Look more closely at worms and how their body structure helps them survive in their habitat. Hand out one worm per student enclosed in a small petri dish with a film of water in the bottom. Ask students to draw what they see (not what they think they see). After a while, ask the students what they have noticed. Ask if they noticed the segments, how they move, the blood vessel, the dark soil in the gut, which is head and tail. Allow more time for the drawing. Show image of worm and relate to what students have found, and which body parts are similar and different to ours. Head, tail, mouth, anus, segments, clitellum, blood vessel. Organs: heart, brain, blood vessels. Try this link for an image: https://thebiologynotes.com/nervous-system-of-earthworm/ How do worms breathe? We breathe by pulling air into our lungs. Worms breathe through their skin, by absorbing the oxygen from water - hence they need to stay moist to keep getting oxygen. How do worms see? (There is no obvious eye). Although we can't see any eyes on a worm, they do have rudimentary eyes. Eyes closed activity to show how worms see: ask students to look up at the light, then close their eyes and notice that they can still see some brightness. While keeping their eyes closed, face away from the light and notice how the light dims. Worms are able to detect where the light is with rudimentary eyes - they cannot focus to see an image but can detect which direction the light is coming from. This allows them to dig down into the soil (away from the light) to avoid predators. How do worms move? They move by muscle contraction and by gripping with the bristles (called setae) on each segment. See these images to show the sequential muscle contractions that move them along:https://www.macmillanhighered.com/BrainHoney/Resource/6716/digital_firs…https://www.researchgate.net/figure/Earthworm-Locomotion-Mechanism-adap… Other worm information: They are both male and female in the same body but still need to mate to reproduce, by joining clitella (the smooth band on their bodies near the head). They are decomposers, eating dead plant and animal matter and turning it into soil. They also aerate soil as they dig through it, making it more habitable for plant roots and other soil animals. Attached documents Worksheet_worm.pdf Worksheet-worm-half_page.pdf Notes Apparently if the worms are on wet paper, you can hear the setae scratching on it. Grades taught Gr K Gr 1 Gr 2 Gr 3 Gr 4 Gr 5 Gr 6
