On-demand dynamic source routing protocol (DSR) is used to detect black hole nodes in the wireless sensor nodes. Various scenarios are simulated using NS2, which is a discrete event network simulator. In this paper, the events are processed in order of their scheduled occurrences and time. First and foremost, the deployment of sensor nodes is done in simulator. Then few nodes are assigned the role of malicious nodes. Finally, the communication among the multiple sensor nodes begins. The communication in network is made using DSR. When the communication ends, each log is maintained in the trace file. Using the trace file, the AWK files calculated several performance factors like the number of packets dropped, decreased throughput, variation in the packets sent and received. These parameters help in interpreting the behavior of malicious and potential suspicious nodes.