Mobile Ad hoc NETwork (MANET) is an autonomous, self-configuring and infrastructure-less system in which various mobile nodes are connected by wireless links. In Mobile Ad hoc NETwork (MANET), various routing protocols are there like AODV, DSDV, TORA, DSR etc. Due to the nature of changing topology and infrastructure less in MANETs there are various issues and constraints which affect the performance of the network like mobility, overhead, battery drainage, delay and interference. Various optimization techniques can be used to find out the best and optimal solution. Nature inspired algorithms are meta heuristics that mimics the nature for solving optimization problems opening a new era in computation.