Like many other insects, vinegar flies produce pheromones to call their conspecifics to an interesting food source. A research team has demonstrated in a new study that the flies' frass also contains these pheromones. Fruits that have been covered by the insects' fecal excretions seem to be especially attractive to other flies. These fruits are probably a more easily digestible food after many flies have been feeding on them. The new results are a first step toward understanding the importance of feces in the communication of vinegar flies.