Security schemes proposed for for Mobile Ad hoc Networks (MANETs) based on node's trust computation consider packet drop as a sign of misbehaving from malicious nodes. However, this may not be always true because of node mobility and limited processing capability feature of nodes in MANETs. As nodes are free to move in MANETs, packet loss may occur due to node mobility, non-availability of next hop nodes, and so on. Moreover, due to frequent data from multiple sources, a forwarding node queue may overflow that causes packet loss. Furthermore, packet loss may also occur due to congestion in the network. To better overcome the packet loss problem discussed previously, the packet loss possible reasons should be analyzed comprehensively in all aspect and then propose a counter strategy against each packet loss reason. In this paper, we analyze the reasons behind packet loss in MANETs comprehensively under different network scenarios. Moreover, we investigate the effect of different network parameters, such as mobility, data rate, and congestion on packet loss. One of the main contributions of this paper is to analyze the causes of packet drop comprehensively in MANETs. This work provides detailed insights in selecting the proper parameters to analyze the behavior of nodes in the network in different context. Moreover, this work also provides help in the design of trust-based security schemes to detect and isolate true malicious nodes in the network.