Can plants hear?
In 1973, The Secret Life of Plants claimed not only that plants can hear, but that they also prefer classical music to rock and roll. The book was rightly rebuffed as pseudoscience, but now a growing number of peerreviewed studies are forcing a bit of a rethink. Cress plants, for example, ramp up levels of defensive chemicals when exposed to just the sound of a caterpillar chomping, while the sound of wind or insect song prompts no such effect. Sweet peas respond rapidly to the recorded sound of a buzzing bee by boosting the amount of sugar in their nectar, and pea-plant roots grow towards the sound of water moving inside pipes. It may not be ‘hearing’ in the conventional sense, as plants lack both brain and ears, but plants do have vibration-sensing receptors and so, at some level, could well be responding to sound. Helen Pilcher