Observation & Inference Insect Game
SC Standards: 6-1 primary indicator 6-1.2 : differentiate between observation and inference during the
analysis and interpretation of data.
Time required: Aprox. 45 mins
Supplies:

Plastic bins (1 per group)

Clothes pins (1 per student)

Eraser tops or other small object (3 per student)

Coin (one per group)

Data table sheet (one per group)

Rulers (one per student)

Timer (1 per group)

Graph paper (optional)

Rulers (optional)
Game concept: Students will play the role of aquatic insects. The game consists of three rounds. In
round 1 players are all herbivores and their goal is to “eat” leaves to survive. Leaves
will be represented by eraser tops or some other small object. Each student must
pick up (or “eat”) 1 eraser to “live” but may not eat more than 3. Round 2
introduces predators. Round 3 introduces a second predator. Herbivores are trying
to stay alive in each round
Set-up:

Split students into groups of 4 to 5

Fill plastic tubs with water (1 per group) until it reaches about half way full

Place erasers in the water (3 per student)

Give each student a clothes pin

Give each group a timer

Prepare a class data table on the board
Round 1: No predator
Explain to students that they are aquatic insects that eat leaves at the bottom of the river and
explain the rules. Tell students they live in a river where all the fish have been removed.

Students take turns “eating” each student gets 15 seconds to pull out as many as 3
“leaves” out.

Students record the number of living insects (students) in their data table.

Collect class data in the data table
Round 2: Predator

Students take turns “eating” each student gets 15 seconds to pull out as many as 3
“leaves” out.

After each after student’s turn, a coin is flipped. If the coin lands on heads the “insect”
have been “eaten” by a fish. If the coin lands on tails they are safe.

Students record the number of living insects (students) in their data table.

Collect class data in the data table
Discussion:

Average the number of surviving insects for each round on the board. Explain that scientists
take averages (statistics) to understand more than isolated observations (like just one
section of river). Averages and statistics help a scientist understand what is happening
overall (ie. average of the whole river).

Graph the averages on the board with the students. Encourage students to decide how to
set up and label axes. If time allows how students make their own graphs on graph paper.

Ask students to point out what on the graph they actually observed (the data points, they
saw each student play). Then ask students what they can infer from the data (ie, the trend).
What happens when more predators are added ? (prey numbers go down) Based on the
class data ask students to predict the number of insects that would survive if another fish
was added.
Round 3:

Play continues as in rounds 1 & 2 (all students can play each round even if they didn’t
“survive” a previous round) however, after each student plays the coin is flipped two
consecutive times. Only two “tails” in a row will result in survival

Students record the number of living insects (students) in their data table.

Collect class data in the data table
Wrap Up:

Average the class data for round 3 and evaluate the prediction

Explain to the students that the prediction they made an inference based on their data was
an inference. Explain how scientists make inferences from their data to explain how things
work.
Pre- MacModS
A herd of deer lived in a forest with no wolves. Then scientists brought wolves to the forest one
wolf at a time every week. They counted the number of deer living in the forest before wolves
were added and after each wolf was brought in. The triangles on the graph represent the
number of deer each time that the scientists counted them.
1)
Which animal is the predator? Which animal is the prey ?
2)
What did the scientists observe?
3)
Can you make an inference that predicts how many deer there will be if a third
wolf is added?
Post MacModS
A group of rabbits lived in a field with three foxes. Then scientists removed foxes from the field
one fox at a time each week. They counted the number of rabbits living in the field to start with
and after each fox was removed. The triangles on the graph represent the number of rabbits
each time the scientists counted them.
1)
Which animal is the predator and which is the prey?
2)
What did the scientists observe?
3)
Can you make an inference that predicts how many rabbits there would be if
another fox was removed?
Names: ___________________________________________________________________________
Insect Game

You and your group members are now insects living at the bottom of a river.

Each insect member of your group has 15 seconds to use your clothes pin to “eat”
leaves. Your hand cannot get wet or you are out.

You need one leaf to survive but you get full after you eat three.

In round one there are no fish in your river. You each take your turn and record the
number of insects (you and your group members) in your group that survived in the
data table.

In round two a fish enters your river. After each insect’s turn, flip a coin. If the coin lands
on heads you were eaten by the fish and don’t survive. After each insect has taken their
turn, record the number of insects that survive in the data table.
Data Table
Number of Insects
Surviving
Round 1 (No Fish)
Round 2 (One Fish)
Round 3 (Two Fish)