In this study, we aim to examine the effects of commonly used pesticides on population size, motor function, and learning in Drosophila melanogaster. Specifically, we examined the effects of metolachlor, glyphosate, chlorpyrifos, and atrazine on Drosophila. Pesticides are toxins used to control pests and weeds in crops and in the past, have been connected to multiple health issues in those exposed. Overall, the results were collected using a negative geotaxis assay, aversive phototaxis assay, and a larval learning assay whose data was averaged. This project can be applied to the 1.8 billion people who are exposed to pesticides and assist in defining the connections in between pesticides and the tested diseases.