Online Social Networks (OSNs) are the core of most communications nowadays, leading to possibly sensitive information exchange. Privacy is an important building block of free societies, and thus, for OSNs. OSNs function as group communication systems and can be build in centralised and distributed styles. Privacy can be achieved in distributed systems as all participants contribute to privacy. Peer-to-peer-based group communication systems achieve this privacy improvement partially, at the cost of additional messaging overhead. In this paper, we introduce ant colony optimisation to reduce the messaging overhead of anonymous communication systems, bridging the gap between privacy and efficiency. We apply our adapted privacy sensitive ant colony optimization to improve routing paths by encouraging re-usage and aggregation. Our first results indicate a 9-13% lower messaging overhead compared to the state of the art, while maintaining privacy.