A Mobile Ad hoc NETwork (MANET) is a collection of autonomous self-organized nodes. They use wireless medium for communication, thus two nodes can communicate directly if and only if they are within each other's transmission radius in a multi-hop fashion. Many conventional routing algorithms have been proposed for MANETs. An emerging area that has recently captured much attention in network routing researches is Swarm Intelligence (SI). Besides conventional approaches, many new researches have proposed the adoption of swarm intelligence for MANET routing.