Wireless sensor networks gains its importance because of the critical applications in which it is involved like industrial automation, healthcare applications, military and surveillance. Among security attacks in wireless sensor networks we consider an active attack, NODE REPLICATION attack and COLLUDING attack. We use localized algorithms, ((ie) replication detection is done at the node level and eliminated without the intervention of the base station) to solve replication attacks and colluding attacks. Replication attacks are detected to using a unique key pair and cryptographic hash function. We propose to use XED and EED algorithm[1] ( authenticates the node and tries to reduce the replication) , with this using the Event detected location , non-beacon node is used to find the location of a malicious node and by a simple threshold verification we identify malicious clusters.