Natural insect repellant
The hypothesis that Deet mosquito repellant is more effective than lemon grass oil, is proven to be true.
The instructions on the label of the insect repellant must be carefully read and followed before use. Caution must be taken especially when children or pregnant women are exposed to the spray. Only a small amount of the repellant should be used on children because they are at risk of reacting adversely.
The science fair project can be repeated by comparing the effectiveness of other natural mosquito repellants like Neem oil.
Try to modify the science project to compare the effectiveness of eucalyptus oil in keeping flies away from food.
Insect repellant - http://en.wikipedia.org/wiki/Insect_repellent
DEET - http://en.wikipedia.org/wiki/DEET
Plant this to repel mosquitoes - http://www.hortmag.com/article/lemongrassmosquitoes
Keep mosquito repellant away from children. Your will need 4 adults who are willing to expose their hands to the mosquitos.