Home School Life Journal

Home School Life Journal ................................................................................................................painting by Katie Bergenholtz

Nature Study Lesson 107: Invertebrates: Earthworms


When we studied snakes, I had forgotten to do an activity that I saw at Homeschool Highlights called “Slithering Like a Snake.” It's purpose is to teach that snakes move in one of four ways...

1.Lateral undulation – sideways waves
2.Rectilineary – straight line
3.Concertina – Coiling
4.Side winding – Angled
After telling them this, I had them try to move like a snake on the floor and then the rest of us guessed which of the four movements they made. They were good sports about doing this activity even though they felt self conscious at first, but they made sure I did not take photos of them, so I have none to show you.
Next we moved on to earthworms. My plan was to dig up some earthworms and to then get some "red wiggler" worms from Katie's composter and compare and contrast the two. But digging where earthworms had been spotted in the past did not prove successful, so we had to complete our nature study with Katie's worms.
We chose not to make a wormery in a jar, because the boys were familiar with Katie's wormery. We put our worms on a wet paper towel so they would not dry out as they need to be wet in order to breathe. Worms do not have lungs, but take in oxygen through the skin and this process needs the skin to stay wet.
We first looked at how they move, to compare them to the snake. Whereas the snake uses it's muscles and scales to move, the worm uses its muscles by squeezing them in and out and uses bristles on its underside called setae.
Worms have both circular muscles, which tighten to make their body thinner and longer, and long muscles which squeeze together to move the rear end of its body towards the front end.

We looked at the rings around their bodies, called segments and looked for the a lighter colored section, which is the clitellum. Since the clitellum in near the front end of the worm, finding the clitellum helps to determine which where the ends of the worm are. This was not as easy to see on the red wigglers as it is on earthworms.
Once the front end is found, you can look for the mouth.

Looking through a magnifying glass one can see a flap of skin that hangs over the mouth. It is called the prostomium, which keeps stuff the worm doesn't like from getting into its mouth. Right under the prostomium is the mouth which is big enough to grab a leaf and drag it into the worm's tunnel. Once the boys had made their explorations, they began drawing their nature journal pages.
Nature journals are encouraged but not required, so they keep them as they wish. They included in their drawings the aspect of the color and length of their worms.
James' was just a sketch of his worm. Quentin wanted to draw about all the things he had learned but needed me to write down the words. I wrote while he narrated what he remembered. He wanted me to put in the correct terms (setae, clitellum) even though he did not remember those.

Sam sketched and wrote about what he observed.



8 comments:

  1. Great study of your earthworms. We are working on a compost bin for the first time and we need to check it for worms. For some reason I didn't even think to do that since we had so many in the garden.

    Great journals and I appreciate the use of the correct body parts....so easy to incorporate this sort of learning during nature study time.

    Thanks for your link,
    Barb

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  2. Barb,
    The kind of compost bin Katie is doing needs a special kind of worm called "Red Wigglers." Regular earthworms, for some reason, won't survive in them. If you follow the link about the composter, it tells in detail how she made it.
    My kids are so used to my using the terms that they have come to expect them! LOL

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  3. Very interesting! We haven't studied worms yet - but, we've been finding them all over, so I think we'll have to at least read up on them.

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  4. Hmmmm, I didn't know worms needed to stay wet to breathe, that does explain much.

    Very cool.

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  5. This is great! Thank you for linking this very interesting and informative post to our BEE WISE meme. We are blessed to learn from your family. My homeschoolers look at worms as just one slimy, wiggly thing. They are not into those kind of things so this will encourage them to handle actual worms to study.

    Thanks for sharing.

    Blessings!

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  6. Great lesson. We did a co-op class earlier in the year with worms. It was really neat to see what they did in those jars with different layers of dirt.

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  7. Yes, and we have been amazed to see how they turn newspaper and food scraps into dark humus. It is almost hard to believe it is real. Every so often Katie has to take out some of the soil because it fills the container. She has to pick the worms out of the soil and put them back into the compost container. She adds more sand, newspaper and food scraps and they begin again their magic! We haven't had to buy potting soil or the like since she began the composter!

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  8. I love your study. The journal entries are wonderful! And we will be coming back to reference your composting. I'm honored by your link to Homeschool Highlights :)

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