Earthworms Unit Study

Are your kids fascinated with earthworms? Well, mine are (although I was not as a child)! So, we are taking a closer look at worms this week. And summer is a great time to study earthworms especially after it rains since they tend to get to the surface due to their tunnels being flooded with water right after it rains. And in the winter, earthworms burrow deeper in the soil below the frost level and curl up with other earthworms for warmth, so finding one in the winter is highly unlikely.

"Moist decomposing wood is a perfect nutrient nursery from which lichens, mosses, flowers, and even other trees can set root and thrive." Nature Anatomy.

Reading Nature Anatomy book prompted us to make an earthworm (using this amazing air-play-dough) and discuss how important earthworms are in our ecosystem. An earthworm can eat pretty much any organic matter that was once living, digesting rotting leaves and breaking them down into a nutrient-rich fertilizer/casts  ~ "worm casting." While food scraps are usual worm 'bedding/food', worms don't seem attracted to material that breaks down slowly like wood chips do. It is amazing how one's scraps (which if left rotting could cause serious outbreaks) are another's favorite food and another's waste is the rich soil we can't live without!  

Earthworms eat rotting leaves, flowers, and fruit, as well as dead insect, tiny stones and bits of dirt which help grind the food.

They eat and eat rotten food and leaves along with the soil. While rotting food, leaves and insects fully digest, soil and tiny rocks come out as a by-product, giving us a nutrient-rich fertilizer/casts  ~ "worm casting.
Earthworms (Little Pebble: Little Creatures) book is a colorful book with simple yet captivating facts about our wiggly friends. 

Yucky Worms book is an absolute must-have book for any little one who would want to be friends with a wiggly, slimy worm! There is so much to these lowly creatures than what meets the eye. Kids are invited to find out where worms live, see how they move, and understand why gardeners consider them friends with the help. To make our study hands-on, I made this muddy sensory bin to resemble the earthworm environment using these insects and our air-play dough earthworm.

To make the mud, I first made muddy cloud dough that looks totally like mud but is absolutely taste-safe (in case you have little ones) by  adding vegetable oil to your flour base (we are using Hemp Protein Powder that had survived its expiration date ~ so that is how our cloud dough got its brown color). If you are using plain flour, simply add brown/black food coloring. We used our mud cloud dough during farm small world play (see here our pig in the mud under our ☀️Summer Themed Unit Study ). For this earthworm environment, I simply added water to make it slimmer. Totally messy sensorily stimulating play!

National Geographic Little Kids First Big Book of Bugs is another amazing resource to learn about bugs and insects. Did you know that a worm is a BUG ~ meaning ANY creepy crawler!

National Geographic Little Kids First Big Book of Bugs

You will find earthworms in any soil except South America, Africa, and Australia! I guess, it is too hot there, and worms need moisture to keep their skin healthy. You will not find earthworm on either of the Polar Regions ~ way too cold there! 

Earthworms (Little Pebble: Little Creatures) book

Earthworms have no eyes or ears, but they can tell dark from light. Its body is made of many rings, called segments and tiny hairs help worms move as they grip soil. 
National Geographic Little Kids First Big Book of Bugs

An earthworm's digestive system runs through the length of its body and includes a mouth, esophagus, crop, gizzard, intestine and a bum (anus). Did you know that an earthworm breath through its skin! Also, earthworms have a closed blood circulatory system and a central and a peripheral nervous system.  Yes, they do have a brain too! And earthworms have over a hundred segments, where muscles on the periphery of each segment enable the worm to move. Similar sets of muscles line the gut, and their actions move the digesting food toward the worm's anus.

To learn about the parts of the earthworm hands-on, we made an earthworm from air-dry-clay and we also made some of the internal organs and parts. Did you know that an earthworm has five hearts! Yes, it has a brain and a digestive system! I also made labels from sticky notes and offered children to match them to body parts. We are referring to Yucky Worms book, which offers amazing insights, such as a fable that if you cut a worm in half, it will keep growing. It is false! The earthworm will die since its main organs would be damaged. I highly recommend this poignant book, where a boy changes his attitude from "Yucky Worms"! to his "friend!"

 Did you know?

• Earthworms are typically active only if water is present.
• Earthworms do not have eyes (although some worms do), however, they do have specialized photosensitive cells called "light cells of Hess".
• Earthworms are hermaphrodites~ meaning that each individual carries both male and female sex organs.
• As invertebrates, they lack a skeleton but maintain their structure with fluid-filled coelom chambers that function as a hydrostatic skeleton.

 

To further explore hands-on, I set this sensory bin made from water beads (hydrogels) to resemble the soil. These water beads are made of non-toxic super-absorbent cross-linked polymer and are fully biodegradable. Just add black food coloring to your clear hydrogels (buying clear ones in bulk is cheaper) along with water and watch them expand before your eyes! See here a video of beads fully expanding in a post ~ Sensory Exploration with Hydro Gel ❤️️ Water Beads ~ Science 🔬⚗️⚖️ 101 🎥Series.

I also added bugs and insects to simulate the earthworm's environment to discuss everything we have learned from books and hands-on observations. 

 

MEASURING THE EARTHWORM

We also made earthworms from home-made play dough (see a recipe here) and I set this invitation to guess which worm is longer.

Adrian labeled each worm according to his prediction.

Adrian then unrolled each earthworm and measured it with the ruler. I explained how to use a ruler and where would the starting point of the measuring be. Since some worms were larger than the ruler, we had to mark 12" point and then measure again. Adrian then had to add the two numbers together. So, to assist with this, I offered Montessori Math Beads. 

During this activity, Adrian learned how to use a ruler. How to determine a measure of something that is longer than a ruler, we reviewed simple addition and he had a chance to think about how the spiral shape differs than a straight line.

Stay tuned for more Earthworms activities ...