The use of inquiry in life science can be particularly daunting because of the additional management and care living systems require. However, there are some low-maintenance organisms that work well in the classroom. One of these is the common fruit fly, "Drosophila melanogaster." Its small size, low cost, easy availability and maintenance, and short life cycle make the fruit fly ideal for the middle school classroom. This article describes a two-part classroom inquiry investigation on population growth using fruit flies. (Contains 4 figures.)