Crystal Cove Conservancy and Crystal Cove State Park have partnered with scientists from UC Irvine’s Center for Environmental Biology and Pomona College to design an ecological experiment to investigate the effect that different types of mulch have on the abundance of non-native Argentine ants in the coastal sage scrub habitat. The Center for Environmental Biology started studying how to use mulch in plant restoration projects in 2018. In 2019, we began working with Dr. Wallace Meyer, an insect ecologist from Pomona College, and ten high school interns from Dana Hills High School to determine how the use of mulch in restoration affects the distribution of ants. Mulch — which is usually made of organic material that is spread around the base of planted seedlings — is used in restoration because it helps retain water, blocks non-native weeds from germinating, and adds nutrients to the soil as it decomposes. But Dr. Meyer has found that the use of mulch leads to higher populations of non-native Argentine ants in the inland areas where he’s previously conducted research. He wants to learn more about how the type of mulch affects the abundance of non-native Argentine ants in the coastal sage scrub habitat at Crystal Cove State Park. 

Now, we need your help to analyze the data that was collected to determine if there are any differences in the abundance of ants between mulch treatments.

For teachers:  If you are a teacher and would like to run this project with your science or math class, feel free to use this Teacher Guide and student notebook pages as a guide!

We would like to know who is taking part in the program! Please fill out this participation form if you have used any of the challenges.

Background on Argentine Ant Experiment

Coastal sage scrub habitat is native to Crystal Cove State Park, and it is one of the most threatened habitats in California. It is found along the California coast and faces threats from land development, climate change, non-native plants, wildfires, and deposition of nitrogen from fossil fuel production (e.g., nitrogen from car exhaust) that leads to more growth of non-native grasses. 

In addition to non-native plants having an impact on the coastal sage scrub habitat, non-native animals also have an impact on the habitat. Argentine ants are a non-native species that are usually found in urban and agricultural areas, but they form large colonies that can force out native ants when they make their way into our coastal sage scrub habitat. 

Because the habitat is threatened and is so important to plants and animals, scientists at Crystal Cove State Park and throughout California are working to restore and protect the habitat. Scientists want to restore the plant communities in the coastal sage scrub habitat by using the most effective type of mulch to encourage native plant growth, but they need to ensure that their decision to use a certain type of mulch doesn’t inadvertently lead to increasing the presence of non-native Argentine ants. To determine whether the type of mulch impacts the abundance of Argentine ants in coastal areas like Crystal Cove State Park, our Crystal Cove Conservancy interns worked with a scientist to set up an Argentine ant study to answer the question, does the abundance of Argentine ants vary depending on the type of mulch that is used around native plants?

How You Can Help!

That’s where we need your help!  You can help us analyze data on ant abundance from winter 2020. To help us, you will need to:

  1. Learn more about the coastal sage scrub habitat and Argentine ants by watching the slideshow and reading through the background materials below.
  2. Make a hypothesis on whether you think you will find evidence of differences in the abundance of Argentine ants between three mulch conditions.
  3. Virtually collect data by watching a video that demonstrates how to sort through the samples using a microscope, looking at images of samples from each mulch treatment, and recording how many Argentine ants were captured in each sample.
  4. Use SageModeler to analyze and graph the ant data from winter 2020 to look for trends.
  5. Share your findings back with us!

Thank you in advance for your help!  We’re really excited to see what you find.  If you have any other questions, please feel free to contact us by emailing

Step 1:  Learn more about the Coastal Sage Scrub Habitat and Argentine Ants.

Start by watching and listening to the Introduction to Argentine Ants slideshow with Erick on Voicethread, which will introduce you to the project.

If you want more information, check out these additional resources:

Step 2:  Develop a hypothesis.

Once you’ve looked through the background materials, think about our monitoring question.

  • Monitoring Question:  If we compare the number of Argentine ants at sites with three mulch conditions, native plant woody mulch, non-native straw-like mulch, and no mulch, will there be a difference in abundance of Argentine ants?

What do you predict you’ll find when you analyze the ant data?  Make a hypothesis and share your initial ideas with us by completing this Google Form.

Step 3:  Virtually collect data.

Watch the virtual data collection VoiceThread slideshow to see how samples from the pitfall traps are analyzed and practice identifying and counting Argentine ants. Flip through images of the samples from each mulch treatment and record how many Argentine ants were captured in each. Submit your data through this Google Form

Step 4:  Analyze the data.

The raw data for ant abundance from winter 2020 is available in SageModeler. 

For some suggestions on how to think about analyzing the data in SageModeler, please check out the Data Analysis Crash Course video on YouTube

Do you have questions about the data that you want answered by Crystal Cove Conservancy staff members or scientists? Submit any questions you or your classmates have to this Padlet.

Step 5:  Share your findings!

We want to know what you found!  Did you notice any difference in Argentine ant abundance between the three mulch treatments?

Please share your findings through a Google Form here!  As part of your conclusions, it would be really helpful to get a copy of any graphs or other data visualizations that you created so that we can share them with Crystal Cove State Park’s environmental scientists. This information will help them better understand the Argentine ant trends, which will help them make more informed resource management decisions.

Would you like to communicate with other students who analyzed the data to talk more about it?  Contribute your thoughts, comments, or questions about the data to this Padlet and see what other people are thinking about the data, too.

Step 6:  Reflect on Argentine ant monitoring.

It’s important for scientists to take some time to reflect on how their thinking has changed. Watch the video of Erick to help you start reflecting on your experiences with the Argentine ant project and answer the following reflection questions.

  1. What did you do during this environmental challenge?
  2. What did you learn? How did your thinking change?
  3. Do you think it is important to monitor the abundance of Argentine ants at Crystal Cove State Park over time? Why or why not?
  4. Did you enjoy analyzing data and sharing your findings to help protect the coastal sage scrub habitat?  What did or didn’t you like about the experience?
  5. Would you like to learn more about ants or other insects, the coastal sage scrub habitat, or how scientists monitor populations there?  If so, what topics interest you?  Do you have ideas of how you could learn more about them?

Are you interested in getting involved in other community science activities? Explore how to contribute to projects at these websites.

Did you enjoy doing the work of a myrmecologist?  Would you like to learn more about entomology careers?  Explore career options by looking at these websites.

Thank you for your help!  If you have any other questions, please feel free to contact us by emailing

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