Food Chains and Food Webs

Food Chains and Food Webs

Science Process Skills

Observing

Communicating

Comparing

Inferring

Materials (per group)

At least 10-15 participants to play the game

Large indoor/outdoor area to play the game

Construction Paper - 3 colors

Plastic sandwich bag for each participant

4-5 liters of popcorn

Masking tape

Scissors

Ruler

Timer

Doing the Activity

Prepare ahead of time:

Make arm band strips out of three colors of construction paper. From one color make enough strips for 3/4ths of the group to be grasshoppers. From another color make enough strips for ½ of the group to be frogs. From the last color make enough strips for 1/3rd of the group to be hawks. (You are making extra strips that will allow you to change the game as you play more times.)

Prepare the sandwich bags. Place a strip of masking tape across the sandwich bag that is approximately 1-1/2 inches from the bottom of the bag.

Do you know what mice eat and what eats mice?
Seeds -> mice -> snakes
You can show the relationship as a "food chain."
Can you think of other examples of food chains?

Save a little popcorn. Spread the rest of the popcorn over the game area. The popcorn will act as plants that grasshoppers like to eat.

Hand out the arm bands. Give ½ of the group grasshopper arm bands.

For the participants that are left, give 2/3 of the group frog arm bands. The remainder of the participants will get hawk arm bands.

Give a plastic sandwich bag to the grasshoppers and the frogs.

Set the timer for 15 seconds.

When you say "go" the grasshoppers should start putting popcorn in their "stomach" plastic bag.

At the end of 15 seconds, send in the frogs. For a frog to eat a grasshopper they must take the grasshopper "stomach bag." Let the frogs eat for 15-30 seconds.

Send in the hawks to eat the frogs. Hawks cannot eat grasshoppers. For a hawk to eat a frog they must get the frog's stomach bags. Let the hawks eat for one minute.

Practice and play the game several times.

Reflecting

How many hoppers got a full stomach? How many frogs? The hawks?

For a grasshopper to survive, popcorn must fill the stomach bag to the bottom of the tape. For a frog to survive, popcorn must fill the stomach bag to the top of the tape. Hawks must have at least one frog to survive.

What would happen if there were only half as many popcorn plants? What would happen to the animals that depend on those plants?

If there were no frogs, what would happen to the plant population? The hopper population? The hawk population?

Do hawks need plants to survive? Explain.

Can you describe some food chains that you are part of?

Are there any plants or animals that are not part of any food chains?

Applying

What rule changes might we make to change the results of our earlier game? How can you make more of a balance in a "5-minute" day?

Play the game again with at least one of your changes. Hint: you might change the number of hoppers or frogs or hawks or you could change the time limits or you could put out more popcorn. How do your new situations relate to real life?

What's Happening

A food chain is a sequence of living things, each of which uses the next, lower member of the sequence as a food source.

A food web is the feeding relationship by which energy and nutrients are transferred from one species to another.

More Challenges

Play a new game. This time provide a safety zone for frogs and hoppers where they can go and be safe. What happens to your food chain?

Look for evidence of plants being used for food. Can you find the animals that are part of this food chain.

Find a ladybug or caterpillar. Put them in a closed but not air tight jar with their food source. Observe the food chain. What would happen if this certain plant or food source was destroyed?

Activity Source

4-H Earth Connections, Department of 4-H and Other Youth Programs, University of Florida Cooperative Extension, Institute of Food and Agricultural Sciences, November 1992. CM Hinton, Publications Distribution Center, IFAS Building 664, University of Florida, Gainesville, FL 32611.

IOWA STATE UNIVERSITY
University Extension

Site contact
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Contact information: Sarah McArdell mcard002@umn.edu
Updated: January, 2000

NNST CYFERNet

	Food Chains and Food Webs
	Science Process Skills Observing Communicating Comparing Inferring
	Materials (per group) At least 10-15 participants to play the game Large indoor/outdoor area to play the game Construction Paper - 3 colors Plastic sandwich bag for each participant 4-5 liters of popcorn Masking tape Scissors Ruler Timer
	Doing the Activity Prepare ahead of time: Make arm band strips out of three colors of construction paper. From one color make enough strips for 3/4ths of the group to be grasshoppers. From another color make enough strips for ½ of the group to be frogs. From the last color make enough strips for 1/3rd of the group to be hawks. (You are making extra strips that will allow you to change the game as you play more times.) Prepare the sandwich bags. Place a strip of masking tape across the sandwich bag that is approximately 1-1/2 inches from the bottom of the bag. Do you know what mice eat and what eats mice? Seeds -> mice -> snakes You can show the relationship as a "food chain." Can you think of other examples of food chains? Save a little popcorn. Spread the rest of the popcorn over the game area. The popcorn will act as plants that grasshoppers like to eat. Hand out the arm bands. Give ½ of the group grasshopper arm bands. For the participants that are left, give 2/3 of the group frog arm bands. The remainder of the participants will get hawk arm bands. Give a plastic sandwich bag to the grasshoppers and the frogs. Set the timer for 15 seconds. When you say "go" the grasshoppers should start putting popcorn in their "stomach" plastic bag. At the end of 15 seconds, send in the frogs. For a frog to eat a grasshopper they must take the grasshopper "stomach bag." Let the frogs eat for 15-30 seconds. Send in the hawks to eat the frogs. Hawks cannot eat grasshoppers. For a hawk to eat a frog they must get the frog's stomach bags. Let the hawks eat for one minute. Practice and play the game several times.
	Reflecting How many hoppers got a full stomach? How many frogs? The hawks? For a grasshopper to survive, popcorn must fill the stomach bag to the bottom of the tape. For a frog to survive, popcorn must fill the stomach bag to the top of the tape. Hawks must have at least one frog to survive. What would happen if there were only half as many popcorn plants? What would happen to the animals that depend on those plants? If there were no frogs, what would happen to the plant population? The hopper population? The hawk population? Do hawks need plants to survive? Explain. Can you describe some food chains that you are part of? Are there any plants or animals that are not part of any food chains?
	Applying What rule changes might we make to change the results of our earlier game? How can you make more of a balance in a "5-minute" day? Play the game again with at least one of your changes. Hint: you might change the number of hoppers or frogs or hawks or you could change the time limits or you could put out more popcorn. How do your new situations relate to real life?
	What's Happening A food chain is a sequence of living things, each of which uses the next, lower member of the sequence as a food source. A food web is the feeding relationship by which energy and nutrients are transferred from one species to another.
	More Challenges Play a new game. This time provide a safety zone for frogs and hoppers where they can go and be safe. What happens to your food chain? Look for evidence of plants being used for food. Can you find the animals that are part of this food chain. Find a ladybug or caterpillar. Put them in a closed but not air tight jar with their food source. Observe the food chain. What would happen if this certain plant or food source was destroyed?
	Activity Source 4-H Earth Connections, Department of 4-H and Other Youth Programs, University of Florida Cooperative Extension, Institute of Food and Agricultural Sciences, November 1992. CM Hinton, Publications Distribution Center, IFAS Building 664, University of Florida, Gainesville, FL 32611.