It sounds pretty gruesome, but a study published in Oecologia in July, 2014 by the University of Missouri-Columbia in the United States found that plants can actually sense the vibrations of something chewing on them and react defensively.
It’s still unclear if this means plants can actually feel the chewing, but this was the first evidence that the nibbling sounds made them react. And we think it would be pretty awful to be able to sense being eaten alive.
The experiment was carried out on a thale cress (Arabidopsis, as it is scientifically called). It showed that when the sound and vibrations of a caterpillar eating its leaves were created, thale cress responded to attack stimuli by producing mildly toxic mustard oils to deter the predator.
According to the study, the more the caterpillar munched on its leaves, the more the plant produced the oils
“Our work is the first example of how plants respond to an ecologically relevant vibration. We found that feeding vibrations signal changes in the plant cells’ metabolism, creating more defensive chemicals that can repel attacks from caterpillars,” said senior research scientist Heidi Appel in a press release.