II.A.1 Part Two-Compiling and Graphing the Data

During this portion of the activity, you and your class will compile all the ant lion data and plot the results on a graph.

Materials:
Each student will need:

  • Pencil
  • Ant Lion Class Data Worksheet
  • One piece of graph paper
Instructions for the teacher:
  1. Copy the Class Data Worksheet on the chalkboard or overhead projector.

  2. Collect data from your student teams column by column as they appear on the Class Data Worksheet. Record these on the board or overhead projector. (You may need a team spokesperson.) Not all teams will have information for each column. Students should fill in their Class Data Worksheets along with you as each team calls out its information.

  3. Once all the data have been recorded on the Data Worksheets, guide students through the steps below to make a graph of the data. The graph you make will address the question: Is there a relationship between ant lion size and pit size?

    1. Draw an outline of the graph. (The x-axis, or bottom, horizontal line, should be approximately 16 squares long. The y-axis, or vertical line, should be approximately 16 squares long.)
    2. Label the x-axis "ant lion size."
    3. Label the y-axis "ant lion pit size."
    4. Put a zero at the point where the y-axis and x-axis come together.
    5. On the y-axis, make a mark every 5mm, starting at the zero. Label these marks .5cm, 1cm, 1.5cm, 2cm, 2.5cm, 3cm, 3.5cm, 4cm, 4.5cm and so on until the largest ant lion pit is accounted for.
    6. On the x-axis, make a mark every 2mm, starting with the zero. Label these 2mm, 4mm, 6mm, 8mm, and so on until the largest ant lion is accounted for.
    7. Now plot the data from the Data Worksheet onto your graph. Start with information collected by team #1. Find team #1's ant lion pit size on the y-axis. Lightly draw a horizontal line to the right.
    8. Next find team #1's ant lion size on the x-axis. Draw a vertical line up from that point until it intersects with your first line. Make an easy to see dot where the lines intersect. Continue doing this until the data from each team are included in your graph.

  4. To interpret your graph, use the examples below.

    • If the dots on the graph form an almost straight line or are scattered in an almost straight line as seen in Example A, there is in fact a direct relationship between ant lion size and ant lion pit size. This means that pit size is fairly predictable. From looking at an ant lion, you would know approximately how large a pit it would make. Or, by looking at the pit alone, you could make a good guess about how large the ant lion was that made it.
    • If the dots are unorganized as in Example B, then no relationship exists between ant lion size and ant lion pit size. This would mean that a big ant lion could make a small pit or a small ant lion could make a big pit, etc.


Results
After completing this activity, students should:

  • Understand predator/prey relationships.
  • Be able to give examples of adaptations sand-dwelling animals have for digging.
  • Understand the concept of an ecological niche.
  • Be able to carefully observe and measure.
  • Be able to participate in discussion and learn cooperatively.

Further Questions and Activities for Motivated Students

  1. Collect as many different kinds of small insects as you can find to feed your captive ant lion. Keep a data sheet to record the time and date, how many and what kind of insects you fed your ant lion, and what was captured and eaten. Continue this for at least one week. Try to answer the following questions:
    • What is the average number of insects that the ant lion eats in one day?
    • What kind of insect does the ant lion prefer?
    • What is the average distance the ant lion can throw the discarded body of its prey?

    Be sure to properly care for your captive ant lion.

  2. Design an experiment to test whether ant lions prefer wet or dry sand.
IIA1-Part 1    Part 2    Student data sheets--Part 1    Class data sheet
Unit II. SAND-DWELLING ANIMALS
A. Ant Lions:    II.A.1
B. Scrub Burrowing Wolf Spiders:    II.B.1
C. Ants:     II.C.1   
D. Glossary    E. Questions for Student Evaluation