The greater short-nosed fruit bat, Cynopterus sphinx, feeds on a variety of fruits, flowers, and leaves. Bats discriminate ripe and unripe fruits of the same species by olfactory cues. Like other neotropical bats, Cynopterus sphinx modifies the leaves/stems of creeper plants and trees as “day roost-tent”. Males construct these tents and prefer to stay with females and their young. An earlier radio-tracking study revealed that after sunset, C. sphinx reaches the previously visited foraging area using spatiotemporal memory and starts searching for food sources with the aid of olfactory cues. Experiments are designed to understand how C. sphinx learn and recognize their food. A series of experiments demonstrate that neuromodulation regulates the downstream signaling molecules in olfactory learning. Specifically, the fine-tuned level of serotonin (5-hydroxytryptamine [5-HT]) in the olfactory bulb (OB) activated the 5-HT1A receptor and serotonin transporter (SERT) to regulate the signaling molecules. Signaling molecules associated with the neuronal circuits in different brain regions, which selectively drive the expression of genes that sorting the preference and aversive olfactory memory. This review focuses on the molecular mechanism of learning and memory in the greater short-nosed fruit bat (Cynopterus sphinx).