Trees have a remarkable ability to sense their own shape and adjust their growth to stay upright. This awareness of body position, known as proprioception, was once thought to exist only in animals. However, in 2012, researchers working with INRAE demonstrated that plants also possess this ability. This internal sense allows plants to monitor their posture and make adjustments that help them grow as straight as possible. Although scientists had established that plants could detect their own shape, the biological processes responsible for turning that information into physical movement remained a mystery. Plants use several kinds of information to guide their growth. They respond to gravity, detect the direction of sunlight, and monitor the shape and position of their own stems. To understand how this internal sense works independently, researchers needed to eliminate the directional signals provided by gravity and light. They developed an unusual experimental system designed to isolate proprioception.