Fourth grade biologists continued their study of ecosystems with a lab about earthworms and their role as decomposers. We each completed this worksheet prior to lab and then again after our lab. Look how much we learned!
After a lesson about worms, we each had our own worm to investigate. Observing our worms use two sets of muscles to move was especially interesting. I demonstrated how these muscles work together with a slinky.
Which abiotic factors will help our worms survive? Click here to watch a short video about worms from SciShow Kids.
So, why are worms wonderful? They have an important role in the ecosystem.
- Worms eat bits of rotting plants, bugs, and animals.
- Their castings enrich the soil.
- They pull nutrients down into the soil.
- Their burrows open up spaces for water and air in the soil.
- Worms are food for many other animals.
Other facts we learned about these interesting annelids:
- Earthworms have no eyes (except in children’s picture books), but they do have light receptors and can tell when they are in the dark, or in the light. Earthworms also have no ears, but their bodies can sense the vibrations of animals moving nearby.
- Earthworms have little rings around their bodies called segments.
- Each segment has little hairs on them called setae that help them move.
- Earthworms can grow a new tail but not a new head.
- An earthworm is both male and female.
- A light colored band forms near the head called a clitellum.
- The clitellum helps the worm form cocoons. Baby worms hatch from the cocoons.
- A worm has five hearts.
- Worms breathe through their moist skin.
- Earthworms eat soil and the plant and animal material in it. They leave behind castings which enrich the soil.
- Gardeners like to have earthworms in their soil.
When I study animals, I am always amazed at how God uniquely created each animal with a niche all its own.