Earthworm Hunt: The Search is On!
Summary
In this field lab activity, which is the first activity of an earthworm unit, students predict and test areas around the school where they believe earthworms will be found. Students will determine two to three locations to use liquid extraction to see if their predictions are correct. After extracting earthworms, students will then briefly observe the earthworms to ensure that all students have the same minimum background knowledge about earthworms.
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Learning Goals
This activity is designed for students to develop common basic background knowledge about earthworms and begin to learn through experience some basic information about earthworm habitats. Students will use critical thinking to determine the best location to use liquid extraction to search for earthworms and observation skills once earthworms are obtained. Basic earthworm handling will be included and students will learn about similarities and differences in the earthworms gathered.
Vocabulary:
-Habitat
-Hatchling
-Juvenile
-Adult
Vocabulary:
-Habitat
-Hatchling
-Juvenile
-Adult
Context for Use
This activity is a whole class lab exercise to introduce what earthworms are to kindergarten students in the spring. Actually getting to handle the earthworms is a way to ensure that all students have some basic knowledge and understanding of what earthworms are and where they are likely to be found around our school. This activity will also generate enthusiasm for a unit on life cycles of something very common, even though it is an exotic invasive species. By the end of the unit, students will also be aware of how to properly dispose of earthworms after fishing, a common activity in our lakes community. Required time will depend on the number of liquid extractions necessary to complete the project. Each liquid extraction location should take 10-15 minutes, as long as the earthworms are active. The best way to ensure that earthworms are active is by doing this lab exercise when the soil is moist, such as just after a rain or during a rain, and choosing a location that is not in full sun. Each liquid extraction will require about 40 grams of ground mustard and one gallon of water. Do not use organic mustard, as that is not as much of an irritant for the earthworms and they may not emerge from the soil.
Depending on the grade level, this activity can include more steps or activities. Students could create maps of the locations where liquid extractions will take place or make predictions of the number of worms that will be extracted at each location. Older students can officially collect and submit earthworms collected to the Great Lakes Worm Watch. Specific information on how to properly do this is online at: www.greatlakeswormwatch.org. This activity may also be used as a culminating experience at the end of an earthworm unit instead of being done at the beginning of the unit as I have planned for my kindergartners.
Depending on the grade level, this activity can include more steps or activities. Students could create maps of the locations where liquid extractions will take place or make predictions of the number of worms that will be extracted at each location. Older students can officially collect and submit earthworms collected to the Great Lakes Worm Watch. Specific information on how to properly do this is online at: www.greatlakeswormwatch.org. This activity may also be used as a culminating experience at the end of an earthworm unit instead of being done at the beginning of the unit as I have planned for my kindergartners.
Description and Teaching Materials
This field investigation will be used to build excitement and establish common background knowledge at the beginning of a unit on earthworms. Materials needed include 40 grams of non-organic ground mustard seed (about 1/3 cup) and 4 liters of water (about one gallon) for each liquid extraction site as well as a container to hold any earthworms that are collected. This mixture will usually sample an area about 35 cm x 35 cm square (about 14" square). Liquid extraction of earthworms is rather exciting to watch, so I often plan on doing at least two or three different extraction sites. Depending on recent weather conditions, the best time to do this activity is when the soil is most and in a location not receiving direct sunlight. Earthworms need moist soil because they breathe through the "slime" on their skin. If the soil is not moist enough, their body processes slow down until soil conditions are better. If environmental conditions have not been favorable, a sure-fire backup plan would be to purchase earthworms, usually night crawlers, at a bait store and have them stored in a container of dirt. However, if you are doing this, please do not let the earthworms go outside, but instead properly dispose of them by using them for fishing or throwing them away. Do not inadvertently help this invasive species spread!
Before students go out to perform our liquid extractions, I would give various clues about this next thing that we will be studying. Students would then brainstorm different ways that we could collect earthworms to study. At this time the students and I would mix our mustard solution to take into the field. Prior to heading outside, students can vote on at least one location in the schoolyard to perform a liquid extraction. The teacher should also choose a location that seems to present the most optimum conditions for your location. Remind students of basic outside rules, such as stay with the teacher and that the time outside is for an experiment, not a time to play. Also share earthworm extraction guidelines on how to properly collect earthworms (after fully emerged from the ground), how to handle earthworms (gently) and any other expectations or rules.
Once everyone has gathered around the first liquid extraction site, review the earthworm extraction guidelines discussed in the classroom. Remove surface debris in this area and slowly pour about half of the mixture on the ground. If you are not applying the mixture to a flat area, have some type of container to prevent the mustard water from escaping. Wait approximately two to three minutes to allow the solution to soak into the ground. Worms that are present and active should start to come up immediately. Wait to collect worms until they are fully emerged from the ground so they do not break into two parts and escape! Collected worms should go into the separate container to be observed after the liquid extraction is finished. You may want to have separate containers for each liquid extraction site to keep the earthworms separate and compare similarities, differences and numbers from different locations. After the initial flush has slowed down, pour more of the solution over the sample area. This will result in emerging worms that are deeper in the soil than those that emerged during the initial flush. Remember to wait a few minutes after the final flush of the liquid to make sure all of the worms present have been collected. If you do not find earthworms during your liquid extraction activity, do not be disappointed, but use this as a learning experience. Either the earthworms are not active due to environmental conditions, usually dry soil, or you may not have earthworms present in that specific area.
After completing all of the liquid extractions, allow the students open observation time with the earthworms collected. Ask some guiding questions, such as: What similarities do you notice? What is different? How to the earthworms feel on your hand? Do you think they have hair? How can you tell when an earthworm is an adult? What questions are you wondering about your earthworm? Give students enough time to fully explore their earthworm and compare with classmates.
Return earthworms to the liquid extraction site where they were collected prior to returning to the classroom. Once students have returned, complete the "Observed," "Know," and "Want to know" sections on an OKWHL chart (Observed, Know, Want to know, How we will find out, Learned). This will be a guiding tool for your classroom unit to be referred to throughout the entire unit on earthworms. If time allows, you may continue with other activities in the unit, such as journaling about their earthworm, reading a non-fiction story, or other related activities. Throughout the unit, continue to refer to the observations made during the field study to help students build their understanding and knowledge of earthworms.
The liquid extraction information was based off of information on the Great Lakes Worm Watch website (www.greatlakeswormwatc.org) and in the book Earthworms of the Great Lakes. Cindy Hale, a research scientist and environmental educator at University Minnesota- Duluth, has compiled this information and is the lead researcher of the Great Lakes Worm Watch project.
Hale, C. (2007). Earthworms of the Great Lakes. Duluth, MN: Kollath + Stensaas.
Before students go out to perform our liquid extractions, I would give various clues about this next thing that we will be studying. Students would then brainstorm different ways that we could collect earthworms to study. At this time the students and I would mix our mustard solution to take into the field. Prior to heading outside, students can vote on at least one location in the schoolyard to perform a liquid extraction. The teacher should also choose a location that seems to present the most optimum conditions for your location. Remind students of basic outside rules, such as stay with the teacher and that the time outside is for an experiment, not a time to play. Also share earthworm extraction guidelines on how to properly collect earthworms (after fully emerged from the ground), how to handle earthworms (gently) and any other expectations or rules.
Once everyone has gathered around the first liquid extraction site, review the earthworm extraction guidelines discussed in the classroom. Remove surface debris in this area and slowly pour about half of the mixture on the ground. If you are not applying the mixture to a flat area, have some type of container to prevent the mustard water from escaping. Wait approximately two to three minutes to allow the solution to soak into the ground. Worms that are present and active should start to come up immediately. Wait to collect worms until they are fully emerged from the ground so they do not break into two parts and escape! Collected worms should go into the separate container to be observed after the liquid extraction is finished. You may want to have separate containers for each liquid extraction site to keep the earthworms separate and compare similarities, differences and numbers from different locations. After the initial flush has slowed down, pour more of the solution over the sample area. This will result in emerging worms that are deeper in the soil than those that emerged during the initial flush. Remember to wait a few minutes after the final flush of the liquid to make sure all of the worms present have been collected. If you do not find earthworms during your liquid extraction activity, do not be disappointed, but use this as a learning experience. Either the earthworms are not active due to environmental conditions, usually dry soil, or you may not have earthworms present in that specific area.
After completing all of the liquid extractions, allow the students open observation time with the earthworms collected. Ask some guiding questions, such as: What similarities do you notice? What is different? How to the earthworms feel on your hand? Do you think they have hair? How can you tell when an earthworm is an adult? What questions are you wondering about your earthworm? Give students enough time to fully explore their earthworm and compare with classmates.
Return earthworms to the liquid extraction site where they were collected prior to returning to the classroom. Once students have returned, complete the "Observed," "Know," and "Want to know" sections on an OKWHL chart (Observed, Know, Want to know, How we will find out, Learned). This will be a guiding tool for your classroom unit to be referred to throughout the entire unit on earthworms. If time allows, you may continue with other activities in the unit, such as journaling about their earthworm, reading a non-fiction story, or other related activities. Throughout the unit, continue to refer to the observations made during the field study to help students build their understanding and knowledge of earthworms.
The liquid extraction information was based off of information on the Great Lakes Worm Watch website (www.greatlakeswormwatc.org) and in the book Earthworms of the Great Lakes. Cindy Hale, a research scientist and environmental educator at University Minnesota- Duluth, has compiled this information and is the lead researcher of the Great Lakes Worm Watch project.
Hale, C. (2007). Earthworms of the Great Lakes. Duluth, MN: Kollath + Stensaas.
Teaching Notes and Tips
This activity is a lot of fun, for both the instructor and the students! The recipe for the mustard water is 40 grams (about 1/3 cup) ground yellow mustard seed to four liters (about one gallon) water. I often use a gallon milk jug because this is easy to shake before applying the mixture to the ground. If you have not done this activity before, you may want to do a trial run without students.
In the past, I have used this field activity midway through studying earthworms. However, I have since realized that some of my students have never touched or observed earthworms. Assumptions were made that each child had held an earthworm before! From now on, I plan on begin each unit with each student having the same common knowledge to build upon!
In the past, I have used this field activity midway through studying earthworms. However, I have since realized that some of my students have never touched or observed earthworms. Assumptions were made that each child had held an earthworm before! From now on, I plan on begin each unit with each student having the same common knowledge to build upon!
Assessment
Students will be reflecting on information learned about earthworms throughout the entire unit. At this point, I am not planning on formally assessing students during our field investigation, other than to make sure each child is participating. Each child will be expected to share at least once while we complete our OKW sections of the OKWHL chart. This informal assessment will help me determine what information children were or were not able to infer and retain during our extraction activity. Then I will better understand what common background knowledge was established during the activity and how to best build on this knowledge.
Standards
Kindergarten IV.B.A. Life Science- Diversity of Organisms: Understand that there are living and nonliving things.