Mobile Ad Hoc Networks (MANETs) are infrastructure less networks that are very dynamic in nature. The main problem with such networks is mobility of the nodes, the nodes are free to roam arbitrarily, thus the topology changes from time to time, and the route acquisition in such a network is always a tedious task. In this paper, the authors describe an algorithm implemented based on a firefly algorithm (an implementation of swarm intelligence). Firefly algorithm capture the nature of fireflies i.e. how they do the task individually and how they coordinate with each other to create a system. This algorithm is compared with the state-of-the art routing algorithm and it thus improves MANETs routing performance in terms of the packet delivery ratio, packet loss, throughput and delay.