The chorus of “Carrot Juice is Murder” begins with the lines “I've heard the screams of the vegetables, watching their skins being peeled, grated and steamed with no mercy . . . ” Well, it turns out the Canadian band The Arrogant Worms was onto something. Plants do scream when suffering.
Researchers found that tomato and tobacco plants make a variety of high-pitched noises. There are different sounds depending on whether a plant is suffering from drought, being cut or unharmed. The actual mechanism behind the ultrasonic shrieks and screams is unclear but might be the sound of air bubbles forming and popping in the xylem (the tissue that allows water and nutrients to flow through the plant).
The noise is in the range that many animals and insects can hear. The scientists hypothesize that other organisms might respond to these sounds. For example, moths might avoid laying eggs on drought-stressed plants. Bats may be attracted to plants that are screaming after being injured by pests with the anticipation that there may be more insects (i.e., bat food) around those plants.
Source: I. Khait, O. Lewin-Epstein, R. Sharon et al. 2018. Plants emit informative airborne sounds under stress. bioRxiv preprint. Dec. 28.