Malaria is a vector-borne disease that currently affects half of the world population and leads to >400,000 deaths/year. Larval and adult mosquitoes use olfaction to locate their human hosts, food sources, aquatic habitats and to avoid harmful substances in their environment. Due to the lack of suitable research tools until very recently, little is known about how individual smell-detecting neurons of mosquitoes respond to odorants. Here I will present the new methods to study how the larvae of malaria mosquito A.gambiae use their sense of smell to detect insect repellents. I will answer this question by monitoring behaviour of wild-type and olfactory impaired larvae, and by recording activity of their smell-detecting neurons with the help of a fluorescent indicator. Findings of this project will inform future work on modifying mosquito preference to smells by genetically changing how their neurons function, as a potential method to control malaria.