WSN is a dispersed sensor network having sensors as its endpoints that can sense and detect the external environment. Numerous routing, power management, and data dissemination protocols are tailored specifically for WSNs, prioritizing power economy in their architecture. The routing protocols used in WSNs might vary depending on the application and the network's design. Detecting and responding to a broad range of security threats in WSNs is possible with an IDS. WSN Intrusion Detection Systems (IDS) are discussed in this article. The inquiry and connection of each arrangement and the favorable conditions and burdens associated with them decide this. "intrusion" refers to any unauthorized or illegal activity inside a network or system. An IDS is a combination of technologies, methods, and resources that are used to detect, analyze, and report intrusions. In wireless sensor networks, trust-based routing methods are prevalent (WSNs). Following a brief discussion of trust models in WSNs, the focus shifts to routing techniques and cluster-based trust management. The pros and downsides of each routing method are also discussed. Because of this, intrusion detection systems (IDSs) exist to stop unauthorized access to a system's resources. There is a common perception that IDSs constitute the second line of defense for data protection.