At least one type of plant can 'hear' itself being eaten and takes measures to save itself. This was reported earlier this month by a new study. The flower plant, called Arabidopsis thaliana, can detecet pattern of vibrations caused by a chewing sound, and launches a chemical defense to deter the voracious worm or other animal eating its leaves.
Researchers already know, from past studies, that plants have reactions to external stimuli such as wind, touch and acoustic energy (playing music for plants). It was the realization that music can affect plants that gave rise to the idea of checking what else plants can hear and react to.
In the study, researchers played a recording of a caterpillar munching on leaves to the plants, while a control group was not played anything. They then waited for 24-48 hours to see what happened. The results were remarkable. In the group of plants that 'listened' to the sounds of chewing, released higher amounts glucosinolates (like mustard oil), an unappealing chemical for the bugs.
so, does this change our perspective on plants as living creatures? Are they 'afraid' when they hear these sounds, thereby using a defense? It is unclear at this point. What is clear, is that there is a lot more to plant life than meets the eye...
This video will you an idea of how the study was performed: