Repelling bee hiss
Biologists in Germany have found that bumblebees repel creatures invading their nests with an ultrasonic hiss. Wolfgang Kirchner of the University of Konstanz and Jacqueline Roschard of the University of Wurzburg showed that the insects produce a conspicuous hissing sound when disturbed, with harmonics of up to 60 kilohertz. The hiss was so powerful that it drove off a mouse sent to a nest by the scientists ( New Scientist , Vol 163, No 2201).