The idea of a plant making noises may evoke a vision of the mandrakes from Harry Potter. But a new study suggests that plants really do produce distress calls when they do not get enough water. They also appear to produce alarm sounds after being cut, with these noises found to come from tomato and tobacco plants, as well as corn and the grapevines used to make Cabernet Sauvignon. Ultrasonic vibrations have been recorded from plants previously, using sensors directly touching them. Now the new study provides the first evidence that plants emit airborne sounds, which researchers estimate could be heard by animals with sharp hearing like mice and moths from up to 16 feet (five metres) away.