Mobile Ad hoc Network (MANET) is formed by a group of autonomous mobile nodes connected by wireless links, in which there is no backbone infrastructure. In this work, an attempt has been made to understand the characteristics/behavior of Ad hoc On Demand Distance Vector (AODV) and Destination Sequence Distance Vector (DSDV) routing protocols when operating in more challenging environment such as frequent change in network topology and node density. The performance differentials are analyzed using throughput, Packet Delivery Ratio and normalized routing load which shall provide an insight about the sensitivity of the protocols under consideration when exposed in more challenging environment. Simulation based analysis of the protocols have been done using NS-2.