Abstract

Objective

In this experiment you will test several household and natural solutions for their effectiveness as an ant repellent.

Introduction

All animals can sense chemical signals in their environment. Some animals even use chemical signals to communicate. One animal famous for chemical communication is the ant. When you see a trail of ants, it is because they are following an invisible chemical trail. This type of chemical signal is positive, and it is called an attractant because it is meant to attract others towards the signal. Other times a signal may be negative, telling others to stay away. This type of signal is called a repellent.

Sometimes repellents can come in handy. We don't like ants to get into our house, so if we can apply a negative chemical signal around our foundation, the negative chemical signal will tell the ants to stay away. Chemical companies will sometimes try to copy a negative chemical signal to sell as an insect repellent. But sometimes these synthetically produced chemicals can have side effects, or be poisonous to pets or small children. Are there other, more natural and less toxic remedies?

In this experiment, you will test different solutions from around your home for their usefulness as an ant repellent. You will use a simple circle test to find out if a substance is a repellent or not. After testing different solutions, perhaps you can find a home remedy that is safer for your family than a commercial repellent product.

Terms, Concepts, and Questions to Start Background Research

To do this type of experiment you should know what the following terms mean. Have an adult help you search the Internet, or take you to your local library to find out more!

• Chemical signal
• Attractant
• Repellent
• Pheromone

• What is a repellent?
• What is an attractant?
• Will repellents or attractants act as a chemical barrier for ants?

Bibliography

• The National Park Service has a very nice background article about ant biology and control:
  NPS, 2003. "Integrated Pest Management Manual: Ants," National Park Service (NPS). [accessed June 6, 2007] http://www.nature.nps.gov/biology/ipm/manual/ants.cfm
• This project was inspired by two projects from the California State Science Fair that investigate natural sources of ant repellent:
  • Ross, M., 2006. "Ants and Plants," California State Science Fair (CSSF). [accessed June 6, 2007] http://www.usc.edu/CSSF/History/2006/Projects/J1918.pdf
  • Shu, C.V., 2006. "The Defense against Ants," California State Science Fair (CSSF). [accessed June 6, 2007] http://www.usc.edu/CSSF/History/2006/Projects/J1922.pdf
• In an interesting twist, the same chemical pheromone that helps ants find their way may have promise in helping Alzheimer's patients in the future. This is an interesting tale of how chemicals in nature can have unexpected, but very exciting applications:
  Segelken, R., 1998. "Cornell News: Ant Recruitment Pheromone," Cornell University, Ithaca, NY. [accessed June 6, 2007] http://www.news.cornell.edu/releases/Feb98/antpheromone.hrs.html
• What happens when there is a "pothole" in the chemical trail? Read this article to find out:
  Sohn, E., 2007. "Pothole Repair, Insect-style," Science News for Kids (SNK). [accessed June 6, 2007] http://www.sciencenewsforkids.org/2007/06/pothole-repair-insect-style-3/

Materials and Equipment

• Q-tips®
• Dixie® cups, smallest size
• Large, white vinyl tablecloth
• Permanent markers
• Different solutions to test:
  • Sugar water
  • Lemon juice (or other citrus)
  • Vinegar
  • Saturated baking soda solution (dissolve backing soda into water until no more will dissolve)
  • Detergents (dish soap, laundry, hand soap, etc.)
  • Commercial ant repellents (get permission and adult supervision for commercial products)
  • Hot pepper oil
  • Tabasco sauce
  • Any other liquid you would like to test!

Experimental Procedure

1. Find a location outside where there are plenty of ants crawling around.
2. Lay out your vinyl tablecloth on the ground in the area of heavy ant activity.
3. Using your permanent marker, mark off areas on your vinyl mat where you will apply different solutions and label them.
4. Pour some of your first solution into a small Dixie® cup and dip a Q-tip® into the solution.
5. Place several ants in the area you have marked off for this solution.
6. Draw a circle around the ant, about 1 inch in diameter. Watch the ant to see if it stays in the circle, or leaves the circle.
7. Write your data in a data table. Make a hatch mark for each ant you observe in the correct column. Here is an example of a data table you could use for this experiment:

   Name of Solution	Total Number of Ants Trapped in Circle	Total Number of Ants Escaping Circle
   Lemon Juice
   Tabasco Sauce
   etc.

8. Keep drawing circles around ants with your test solution until you have tested at least 20 ants total and recorded your results.
9. Repeat steps 4–8 for each different solution you want to test.
10. Make a graph of your data. For each solution, make a bar for the number of ants that are trapped inside the circle, and another bar for the number of ants that leave the circle.
11. Potential repellents will be solutions that trap the ants inside the circle. Which solutions make the best repellents?

Variations

• Once you find some potential repellents, you can figure out which ones work the best. Try the circle test again, but time how long the ant stays trapped in the circle in seconds using a stop watch. Then you can compare how long the potential repellent will last. Which repellents last the longest?
• You can also use a timed circle test to experiment with different concentrations of repellent. How diluted can your solution be and still act as an effective ant repellent?
• You can also try a similar test with dry or powdered substances, but you will not need to use a tablecloth. For a hard, dry substance like chalk, just draw the circle by rubbing chalk against the sidewalk. For a powdered substance, like baking soda or sugar, just sprinkle the powder in a circle around the ant. Can you find some powdered or solid substances that work as ant repellents?

• For more science project ideas in this area of science, see Zoology Project Ideas.

Credits

Sara Agee, Ph.D., Science Buddies