Drosophila melanogaster is a type of very small fly that scientists study a lot. They study it because it helps scientists understand how organisms work and how diseases work, which can help scientists figure out ways to make people healthy. They also do a lot of experiments with Drosophila to learn how different things can affect the fly and how they can be changed over time. Because they are so small and easy to keep in the lab, it makes it a great organism to study.