Wireless Sensor Networks consists of tiny devices capable of processing, routing the sensed data and are capable of detecting the intruders. The process of detecting any suspected(anomalous) moving object(attacker) within the reach of a Wireless Sensor Network area is referred to as intrusion detection. In this paper, we propose an algorithm to detect the intruder by the cluster heads in a 2D and 3D homogeneous Wireless Sensor Networks. This algorithm overcomes the attacks on implementation and also, reduces the energy consumption. The proposed algorithm considers Single Sensing and Multi-Sensing Intrusion Detection using minimum number of sensor nodes and a probabilistic model has been developed for both 2D and 3D homogeneous networks. Simulation results show that the power analysis attack and energy consumption is minimized by activating only few sensor nodes for detection and using only few sensor nodes for processing of data. The performance of the proposed algorithm is better compared to using all the sensor nodes for detection where the energy consumption is more.