Description: Babyfood jar pitfall traps containing different baits are placed in different areas of the schoolyard over a twenty-four hour period of time. Students count and identify the different animals caught in their pitfall traps and then post their data for others to analyze and compare.

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, 30 minutes to set out traps, 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. NOTE: Traps should be set out for 24-hour periods.

Teacher Information:

Student Instructions Available to download as a PDF file.

Needed Materials: blunt tweezers, 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), something to cover each trap (old floppy drives work great for this), hand spade, several plastic containers with lids or resealable plastic bags, 10 empty large 180 ml (6 oz.) glass baby food jars ;3 grams (1/8 oz.) of one or more of the following baits: apple, meat, cheese, peanut butter, syrup; 40 small flat stones, rubber stoppers or blocks of wood approximately 1 cm. square, 10 slightly larger rocks to keep trap covers from blowing away. (NOTE: If you plan to run several different tests in different locations, you may need more than the suggested amount of materials.)

Safety Rule: You can avoid direct contact with the animals you have trapped by using tweezers and/or a paint brush to move them from the pitfall trap to a jar or resealable plastic bag.

Procedure :

Student Information: The following information will provide you with the steps for setting up your pitfall trap and collecting the trapped organisms. It is important to hold all of the variables constant except for those that are being manipulated. Constant (or controlled variables) would be such things as: the size of the baby food jar, the amount of time the experiment is conducted, the amount of food, the position of the jar in the ground, the cardboard covering, etc. Manipulated (or independent) variables would be those things that we change to see if the response will be different, such as: type of food, location of the jar, etc.) The responding (or dependent) variable for this experiment will be the number and variety of animals you catch in each of your jars. 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.

The reporting form for this experiment is set up so that you can determine how many traps you want to put out, where you want to place them, and what baits you want to use. NOTE: Be sure to include a control pitfall trap at each chosen site which will have no food in it. 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 several pitfall traps that are exactly the same and then compile an average of your data before submitting it. You can get similar results by repeating the experiment three or more times

Steps to Setting up and Collecting from the Pitfall Trap

• 1. Click on “Login to Enter Data” at the Pitfall Trap Investigation web page link provided above (Note: You will need you user name and password to do this). Once you are there, click on “Add New”.  What comes up is the data collection sheet that will be used in this investigation. Complete any pertinent information and also choose the appropriate choice listed in each "dropdown" box (Ex. The location for your trap, your bait, etc). 
• 2. Print the form and place it on your clipboard. Click "Add" so that your form, and your completed work, to this point, will now be in the list when you return to enter your data.
• 3. Choose a location for your pitfall traps. Look for places that will not get a lot of human interference for a twenty-four hour period.
• 4. Add 3 grams of bait to the first baby food jar.
• 5. Use the marker to write the name of the bait and location on the jar.
• 6. Use the hand spade to dig a hole in the ground that is just a little bigger than the jars being placed at each selected location.
• 7. With the lid loosely attached, place the baby food jars into each of the holes so the tops are at ground level, and then pack dirt tightly around each of the jars.
• 8. Unscrew the lids and leave them sit right on top of the jars. Finish packing the dirt right up to the lips of all of the jars. Remove the jar lids and any extra dirt. Try to make the site look natural and make the lip of the jar as level to the ground as possible.
• 9. Place 4 small stones (rubber stoppers, wood blocks) in a 20 cm. square around each jar and place the cover (floppy or wood block) on top of the stones. This will act as a roof to protect trapped animals from rain and direct sunlight.
• 10. If you use something light in weight to cover your trap, put a larger stone on the cover to keep it from blowing away.

  

• 11. Repeat the above steps for all of the jars you plan to use. Remember to leave one pitfall trap containing no bait at each site for a control.
• 12. After 24 hours return to the traps.  Screw the lids onto the jars so they will not pull off.
• 13. Remove the jars from each of the holes and be sure to record the location and the bait that was used. If you were able to label your jars in the beginning this step is not necessary.