Wildlands Sweep Net Experiment

 

Description: Students use sweep nets to capture animals living in different parts of the Wildlands. They then compare their findings, draw conclusions and make inferences about the locations, numbers and varieties of animals found.

Grade Levels: 4-12 (Note: This experiment can be simplified or made more challenging depending on the developmental levels of your students. See Teacher Information.)

Approximate Time Involved: One or two 30-minute classroom planning sessions, 20 minutes to conduct a control sweep, 30 minutes to conduct the actual sweep(s), 30 minutes to identify and count animals, 20 minutes to enter data online, one or two 30-minute classroom sessions to examine results, state conclusions, draw inferences, and make recommendations. We also hope to repeat the experiment in the fall and spring to allow students to compare their data at different seasons of the year.

National Science Standards Addressed:

Content Standard A: As a result of activities in grades K-12, all students should develop

  • Abilities necessary to do scientific inquiry
  • Understanding about scientific inquiry

Content Standard C: As a result of activities, all students should develop understanding of:

  • (K-4) Organisms and environments
  • (5-8) Structure and function in living things
  • (5-8) Populations and ecosystems
  • (9-12) Interdependence of organisms

Program Standard D: The K-12 science program must give students access to appropriate and sufficient resources, including quality teachers, time, materials, and equipment, adequate and safe space, and the community.

  • Good science programs require access to the world beyond the classroom.

Teacher Information:

Schoolyards, wetlands, fields, woodlands, and other outdoor areas are homes for a host of small animals--insects, spiders, mites, etc.--that you rarely see. A sweep net can be used to capture these small creatures so you can examine their numbers, life cycle stages, size and varieties. You can also redesign and test your sweep net to see if you can increase its effectiveness.

Challenging Your Students to Be Problem Solvers:

To make this experiment more challenging to your students, you might just want to pose a question such as: Using a sweep net, conduct an experiment to determine the type, variety, and life cycle stages of the macro-invertebrates living in the Wildlands. Using an insect net, determine number of (leafhoppers, grasshoppers, crickets, spiders, etc.) living in the Wildlands. What square meter area in the Wildlands will produce the most organisms in a sweep net? Design and conduct an experiment to measure the number and diversity of macro-invertebrates living in the grass found within the Wildlands. Design a sweep net that will allow you to capture the largest number of organisms within a given area in the Wildlands. Design an experiment to determine if there is any difference in the number and types of organisms caught in the grass on the north, east, west, and south side of the school building.

This should become a team exercise where your student groups might each develop and write a hypothesis, list the materials they would use, the number of each item, and a procedure for conducting the experiment. An excellent way to assess this activity is to have the teams repeat each other's experiment to see if they achieve the same results. This will also mirror the real world challenges facing a research scientist, who can only expect to gain recognition when others are able to replicate her experiment.

Needed Materials: Small paint brush, magnifying glass, animal identification charts or field guides (Golden Guides are inexpensive and fairly accurate identification books), felt-tip marker (indelible ink), 20 one-quart or larger zip-lock plastic bags, 5 or more sweep nets to allow everyone an opportunity to do a sweep, 5 pair of cotton gloves. (NOTE: You can purchase inexpensive 5-gallon paint straining bags for around a $1.00 each at your local Sherwin Williams paint store, or other paint stores. They can then be sewn onto coat hangers to make inexpensive sweep nets.) (NOTE: If you plan to run several different tests in different locations, you may need more than the suggested amount of materials.)

Safety Rule: It is likely that some stinging insects will be captured in this activity. The cotton gloves will help protect the hands of the person who must grasp the net and shake the animals into a zip-lock plastic bag. If there are any animals still caught in the net, you can avoid direct contact by using a paint brush to remove them. NOTE: Play it safe and make sure that your school nurse has an Epi-pen and knows how to deliver a shot to a student who may have an allergic reaction to an insect sting.

Procedure:

Student Information: The following information will provide you with the steps for setting up your sweep net experiment. It is important to hold all of the variables constant except for those that are being manipulated. Constant (or controlled variables) could be such things as: the size of the sweep net, the area to be swept, the methods for conducting the sweep, etc. Manipulated (or independent) variables could be those things that we change to see if the response will be different, such as: the location of the sweep, the dates and times of the sweep, the design of the net, etc.) The responding (or dependent) variable for this experiment will be the number and variety of animals you catch in your sweep net. NOTE: Temperature is one variable that will be difficult to control or intentionally manipulate in this experiment. However, from your experiments, you may be able to infer as to whether temperature has any impact on the number and variety of animals collected. Can you think of some other variables that may be hard to control?

The reporting form for this experiment is set up so that you can determine how many sweeps you want to conduct, where you want to do the sweeps, and the times that you want to sweep. NOTE: You may want to do several "control" sweeps beforehand to determine the best procedure to follow when actually conducting the experiment. Also remember that a good scientific experiment is repeated a minimum of three times. Therefore, your data will be more accurate if you set up sweeps of areas that are exactly the same and then compile an average of your data before submitting it.

Steps to Conducting the Sweep Net Study

1. Choose the location(s) for your sweep net experiment. Look for places that have different types of ground cover. NOTE: It may be that some areas have taller grass than others. Some places may be drier or wetter than others. Some places may have different plants, or a variety of different plants. Some places might always be in the shade while others are in the bright sunlight.
2. Measure an area that is one square meter in size for each site that you intend to sweep.
3. Make certain that your sweep net is assembled and ready to go. Bend your coat hanger circle so that there is a flat side to your sweep net. A good shape is a triangle with the handle extending from one of the points.
4. Practice making a back and forth "figure 8" swing in such a way that the opening of the net is always first to sweep the area.
5. Pick an area as a "control" site and practice your sweep net swing. Go back and forth over the area using the "figure 8" motion until you have swept the entire square meter site.
6. At the end, quickly swing the sweep net through the open air to force the captured animals to the bottom of the net.
7. Immediately grasp the bag about half way up to make sure your captured animals do not escape. NOTE: The person doing this should be wearing gloves to prevent the rare chance of being stung.
8. While another student holds the zip-lock plastic bag open, place the net over it, loosen your grasp and turn it inside out into the bag. Carefully shake and remove the net from the bag, making certain to seal it so the animals do not escape.
9. You can now repeat steps 5-8 at all of your actual test sites. NOTE: Be sure to record the information that is needed to identify each of your test sites on the submittal form.
10. Once you have captured the organisms, you can observe them through the zip-lock bag and try to: identify their species, family and/or class, take a count of each type or group, and determine the stage of their life cycle (pupa, larvae, immature adult, and mature adult).
11. Once you have gathered all of the necessary information, release your animals back into the area(s) where you originally captured them.

Below is a list of questions that can be used to stimulate student discussions. If your students are at a developmental level where you are able to challenge their higher level thinking skills, then only present them with the first set of questions from each group below. Use the second list of questions as a way to stimulate thinking when you students seem unable to expand their knowledge on their own.

Examining Local Results

Discussion Questions that Require More Critical Thinking Skills:

  • What were your conclusions for this experiment?
  • What could you infer based on your conclusions?
  • How would you design this experiment differently the next time?

Discussion Questions that Require Less Critical Thinking Skills

  • What types of animals did you find in your sweep net?
  • Did different sites produce different numbers and types of animals caught?
  • If the answer to the above question is "yes", what site was most successful in terms of animals caught?
  • Did certain animals prefer certain kinds of environmental conditions (dry or wet, warm or cold, tall or short grass, etc.)?
  • Did the outside temperature have any impact on the number of animals caught?
  • What types of animals are not likely to be caught in a sweep net?
  • If you also did the pitfall trap experiment, what comparisons can you make?
  • Would you expect to capture the same animals in your sweep net if you conducted this experiment several times throughout the year? How could you test your predictions experimentally?

Critter Links

Entomological Society of America This site has a special "kids" page for insects.

Monarch Watch Participate in a migratory census of butterflies.

Children's Butterfly Site This butterfly site is maintained by the United States Geological Survey.

Young Entomologists' Society, Inc. If you really like to explore the insect, spider, and minibeast world, check out this site and become an amateur entomologist.

This activity was adapted from a lesson created by

Contributors to this activity include Mike Schneider. An on-line version can be found @  http://web.stclair.k12.il.us/splashd/sweepnet.htm