Recent research in defense mechanisms against packet dropping attacks in wireless ad hoc networks focuses on developing adaptive, trust-based, and collaborative detection frameworks to counter malicious nodes that intentionally drop data packets and degrade network performance. Modern solutions employ reputation systems, watchdog monitoring, and acknowledgment-based mechanisms to identify nodes exhibiting abnormal packet forwarding behavior. Trust computation models dynamically evaluate each node’s reliability based on packet delivery ratios and historical interactions, while cryptographic and acknowledgment authentication techniques enhance data integrity during transmission. Machine learning and game-theoretic approaches are increasingly applied to distinguish between intentional drops and congestion-induced losses, ensuring accurate detection with minimal overhead. Recent advancements emphasize lightweight, distributed, and energy-efficient defense schemes that maintain high packet delivery ratios, minimize false detections, and sustain secure communication in resource-constrained and dynamic ad hoc network environments.