| Complexity level: | 5 |
| Project cost ($): | 20 |
| Time required: | 1 day to prepare, 1 hour for the science project experiment |
| Material availability: | Easily found. |
| Safety concerns: | Handle ants carefully. They bite! Adult supervision or assistance required |
Hypothesis
Lemon juice is more effective as a pesticide, than apple, tomato or carrot juice, against ants.
Overview
Natural pesticides
Pesticides are substances used to kill or to keep insects and pests at bay, away from our homes, gardens and farms. These insects are a nuisance as they damage property and cause diseases. These pests are also unhygienic. Most commercially available pesticides contain chemicals that are harmful to our health. When we empty a can of insecticide spray, some of these fumes are inevitably inhaled and enter our lungs. The pesticide used by farmers also seep into the soil and contaminate our food chain and drinking water.
An alternative to using chemical pesticides is natural pesticides. These are naturally produced substances in plants. These natural pesticides are usually very safe for use and cause no harrm to the environment. However not all natural pesticides are completely safe. Nicotine which is derived from tobacco is very addictive and to some extent, even more toxic than many chemical pesticides.
Examples of natural pesticides are lemon juice, bay leaves or cucumber peel. Borax, a salt crystal, can be used in powder form to keep termites and cockroaches away. Honey can be used to attract flies and trap flies – once they flies land on the honey, the honey sticks to their feet and prevents them from escaping.
Scientific Terms
Materials
The materials required for this science fair project:
- 1 empty bottle
- black ants (collected from an ant hill)
- 1 pair of gloves
- 1 lemon
- 1 apple
- 1 tomato
- 1 carrot
- 4 plastic cups
- 1 juice extractor
Procedure
1. For this science fair project, the independent variable is the type of juice used – lemon, apple, tomato and carrot. The dependent variable is the movement of ants - in and out of the circle. This is determined by observing if the ants cross the line made from the juice. The constants (control variables) are the type of ants used, the size of the circle, the concentration of the juice and the width of the line.
2. A small ant hill is located. Wearing latex gloves, collect as many ants as possible in an empty bottle. Be extremely careful to avoid being bitten. Do not let the ants crawl over unprotected bare skin. Adult assistance is required.
3. Once you have collected the ants, close the cover and put the bottle aside.
4. Using the juice extractor, prepare lemon, apple, tomato and carrot juice and pour them into 4 cups.
5. Draw four circles on the floor or table using the extracted juices. Ensure that the lines are thick, and wet with juice. Open the bottle containing the ants and release some of the ants into each of the circles.
6. Observe if the ants are able to cross the lines drawn, and exit the circle. Record the observations in the table below.
Results
It was observed that lemon juice was effective in keeping the ants within the circle. The apple juice, tomato and carrot juices were not effective.
| Natural pesticide | Lemon juice | Apple juice | Tomato juice | Carrot juice |
| Result | Y | X | X | X |
Y - the ants did not exit the circle
X – the ants escaped from the circle
Conclusion
Out hypothesis that lemon juice is more effective as a pesticide, than apple, tomato or carrot juice, against ants, has been proven to be correct.
Using natural pesticides derived from plants, vegetables or fruits are a better and safer way of keeping insects at bay. Their effectiveness may be for a short period of time and they be a more expensive means of pest control, but they are safer and more environmentally. Regular use of chemical pesticides can be harmful to our health, especially to our children. These insecticides can enter our bodies through inhalation of fumes or the contamination of food and drinking water, causing various types of illnesses.
Also consider
Would your observations be different if this science fair project were to be repeated using different types of insects like cockroaches or termites?
The science project experiment can also be repeated using different types of natural substances like vinegar, saltwater, garlic oil or tea.
References
Natural pesticide alternatives - http://www.essortment.com/all/pesticidesalter_rfhc.htm
Natural pesticides - http://www.livingwithbugs.com/natural_pesticides.html
How to kill ant with natural pesticides - http://www.associatedcontent.com/article/685561/how_to_kill_ants_with_natural_pesticides_pg2.html?cat=32
