Norwood Science Center. Animals Grade 1

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Quentin Newman
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1 Norwood Science Center Animals Grade 1 Background Information: Earthworms are Scavengers; they break down dead plants and animals and return them to the soil. Scavengers are an important link in a Food Chain/Food Web. They are organisms that are able to break down large molecules into smaller parts. Scavengers can be found at any link of a Food Chain. They return the nutrients that are in a living thing to the soil. Without these organisms, future generations of plants would not have the nutrients they need to grow. The earthworm (Lumbricus terrestris) lives in a subway under the ground. It makes its own tunnels as it moves about. Its body can open at both ends, like a tube, and dirt can pass through it as it moves. The soil that the earthworm lives in is often mixed with seeds, very small live animals, and bits of dead plants and animals. This is food to the earthworm. The earthworm lives in soil and gets its food from soil, too. The food is taken from the soil as it moves through the worm's body tube. There are special parts of the tube for doing this job. The earthworm does some of the same things a farmer does. It loosens the soil as it burrows, just as the farmer loosens the soil with a plow. Farmers add fertilizer to the soil to make plants grow better. Earthworms fertilize the soil by mixing their own wastes or "castings" with the soil. The mixing is done inside the body. When the mixing is put out, it helps plants grow better. Earthworms also help to decompose dead plant and animal material into simpler parts that can be used again by new organisms. An earthworm has no nose and no lungs; it breathes through its skin. But the earthworm's skin must be moist or it cannot breathe. Page 1

2 Therefore, we find earthworms in damp ground. If there has been no rain for a long time and the earth dries up, the worms will burrow deeper, looking for dampness. The main sense organ of earthworms is their skin. An earthworm's skin is very sensitive to moisture, temperature, touch and light. The earthworm actually uses its skin to see, feel, and detect moisture. The worm breathes by taking air out of the moist soil directly through its skin. Since its skin is tender, it prefers a smooth environment to a rough one. Its skin senses light allowing worms to tell when it is day or night. When you look at an earthworm, you will see that the body is divided into rings, or segments. The number of segments in a fullgrown earthworm varies between 120 and 175. The earthworm and all its relatives have these rings. Rings are one way of telling this group of worms from other groups of worms. You will find small stiff bristles on the earthworm's body. The earthworm uses these bristles to grip the ground when it is crawling. It can also use them to hook itself onto the sides of its tunnel so that it is hard to pull the earthworm out. You may have tried to pull an earthworm out of the ground. If you have, you know how tightly it can hold on. The earthworm does not have eyes, but the skin at both ends of its body responds to light. The earthworm does not respond to sound, but it responds very strongly to vibrations in the ground. It does not have much sense of smell. Earthworms are nocturnal and rarely come out of the ground except at night. The worm has a ring, or Clitellum, that is located towards the front end of the animal. Since all worms are hermaphroditic, they possess the sex organs of both genders. After fertilization, the cocoons are formed at the Clitellum, and the eggs are cast off to hatch a later time. We ll leave the worm reproduction story for the later years. Page 2

3 TITLE: PURPOSE: MATERIALS: EARTHWORMS Observe earthworms and determine their features (2-3 students per group) Earthworm (1) Container (1) Paper towel (for floor of container) (Per classroom) Spray bottle of water Baby wipes PROCEDURE: 01. Students are to take notes prior to handling the worms in order to minimize the spread of germs and dirt. 02. Students are to draw a large S in the middle of the page. They draw another one next to it, connecting the ends. 03. Roughly 1/3 of the way from one end the students are to draw a rounded rectangle inside the S. This represents the Ring, or the Clitellum. Students should label this body part with the correct word. 04. The Ring is closer to the front of the worm. The students should label this end of the worm as the mouth. 05. Between the ring and the mouth, along the bottom, or ventral, surface are the setae. The setae are bristles that allow the worm to hold onto the dirt as it makes its way underground. 06. Students label the bristles, or Setae. 07. Students are to clear their desks. 08. Get the room as dark as possible, group the students. Page 3

09. Distribute containers with a damp paper towel at the bottom. 10. Place one earthworm on the damp paper towel. It is important to keep the worms wet.

4 09. Distribute containers with a damp paper towel at the bottom. 10. Place one earthworm on the damp paper towel. It is important to keep the worms wet. The teacher might find it helpful to dip each worm into a little water for a quick bath. It removes dirt and allows the worm a maximum of moisture. 11. Have the students watch the worms for a few minutes. 12. Ask students the following questions: What color are the earthworms? How do earthworms move? Do they ever move backwards? Can you tell which is the front end of an earthworm and which is its tail? Can the students find the ring? mouth Bristles (Setae) Ring (Clitellum) rl= M:&tbnh=108&tbnw=94&prev=/images%3Fq%3Dearthworm%26svnum%3D10%26hl%3Den%26lr%3D Page 4

5 13. Have students answer YES or NO to the following questions and tell what they observed. Does an earthworm have: a. eyes? b. ears? c. legs? d. nose? e. mouth? 14. Have students describe any other special features they notice. 15. If a student would like to hold a worm, they need to have wet hands. The students place a hand over the container. The teacher moves from group to group spraying water on the hands of volunteers. 16. Students are not to pinch a worm in order to pick it up. They pick it up like they would pick up a strand of cooked pasta; they roll the worm into a corner and try to scoop the worm up with the fingers. The worm should rest in the palm of their hand. 17. Students should hold the worms a few inches over the bottom of the container. If there is a sudden departure of the worm from the hand the worm will only fall a short distance. 18. When the students, or the teacher, has had enough of the worms the teacher collects the containers and returns the worms to the appropriate container. 19. Every student, even those that did not touch a worm, is to receive a baby wipe. The teacher instructs the students in the correct technique for hand washing. 20. Before the teacher brings the trashcan to collect the wipes, the students are to fold the wipes and wipe off their desks. Page 5

6 CONCLUSION: 01. Review all the observations students made about earthworms. 02. Check earthworm drawing for accuracy in science notebook. SOURCE: 01. Life Science Activities for Grades 2-8. Science Curriculum Activities Library, Parker Pub. Co., Inc., West Nyack, NY, Critters. AIMS Education Foundation, Life: Activities and Explorations. Fabiano and Liberson, Page 6

Wonderful Worms. OBJECTIVES Worms to the Wise To Learn: Why are worms important? Nature s Plows / Gardener s Friend.

Wonderful Worms. OBJECTIVES Worms to the Wise To Learn: Why are worms important? Nature s Plows / Gardener s Friend. Take one carton of worms per classroom. Two students per one worm The worms are in the refrigerator in the workroom. Keep worms refrigerated if stored at home. Transport worms in provided cooler bag OBJECTIVES