Animals use a number of different mechanisms to acquire crucial information. During social encounters animals can pass information from one to another but, ideally, they would only use information that benefits survival and reproduction. Therefore, individuals need to be able to determine the value of the information they receive. One cue can come from the behaviour of other individuals that are already using the information. Here we study how individual decision-making is influenced by the behaviour of conspecifics in Drosophila melanogaster. We analysed how uninformed flies acquire and later use information about oviposition site choice they learn from informed flies. Interestingly, after social interaction, uninformed flies tended either to collectively follow the choice of the informed flies or to avoid it. Using social network analysis, we show that this discriminating decision-making process seems to be based on the level of homogeneity of the social network. Uninformed flies were not influenced by how frequently they observed a behaviour in informed peers; rather, they chose to follow the information they acquired from informed flies that exhibited the behaviour consistently. More generally, further examination of a previous extended dataset confirmed the evidence that the information informed individuals transmit through their behaviour can either encourage or discourage specific oviposition site preference in uninformed peers, and we demonstrate the main role of social network structure on the learning process.