Part 2/6:
One of the most fascinating developments is the identification of ultrasonic squeals emitted by stressed plants. These high-frequency sounds, inaudible to humans, serve as warning signals to neighboring flora. When a plant faces threats such as physical damage or predation—say, from humans knocking them down or insects attacking—they emit these ultrasonic calls to alert nearby plants. This revelation marks a significant milestone, as scientists have now observed these communication signals directly for the first time, transforming our understanding of plant behavior.