IoT devices interact in a smart home ecosystem by leveraging network connectivity and interoperability. Each device, such as smart thermostats, lights, and cameras, communicates with one another and a central hub, enabling users to control their home environment remotely. These interactions often involve exchanging data to automate processes, enhance energy efficiency, and improve overall security. Through protocols like Zigbee or Z-Wave, the devices can work in harmony, creating a seamless and user-friendly living experience that adapts to the inhabitants' needs.