<p>The significant role of routing in the Internet of Things (IoT) has led to the introduction of various routing protocols tailored for this crucial network. Among these protocols is LOADng-IoT, an on-demand routing protocol designed specifically for IoT environments. While LOADng-IoT aligns well with IoT requirements, it lacks inherent security mechanisms, leaving it vulnerable despite its efficiency. To address this limitation, a more advanced protocol named QAT-LOADng (QoS Aware Trusted Lightweight On-demand Adhoc Distance-vector routing-Next Generation) has been developed as an enhancement to LOADng-IoT. QAT-LOADng leverages the Ant algorithm and incorporates a reputation system to bolster security. The primary objective of QAT-LOADng is to establish trust in routing and data transmission through a two-stage process. The first stage focuses on trust-based routing using the Ant algorithm, while the second stage involves data transmission with trust evaluation. Simulation results demonstrate that QAT-LOADng not only ensures reliable routing and data exchange but also enhances the overall quality of routing and data transmission. Specifically, it shows a 7.9% improvement in packet delivery ratio (PDR) compared to LOADng-IoT, along with lower energy consumption and overhead when compared to existing protocols.</p>