Smooth cut

Biologists use vibrating blades to neatly slice tissue for microscopic examination. While scientists thought of this technique only about 50 years ago, a biological version has existed for millions of years, sayl a team of scientists led by Jurgen Tautz of the University of Wurzburg, Germany (Science. Vol 267, No 5194).

The team reports that leaf-cutting ants emit chirps that make both the ant and leaf vibrate at a frequency of 1,000 hertz, allowing'the insects to cut leaves smoothly.

The scientists simulated the ants' cutting process with isolated ant mandibles in a vibrating device. They found that it was more difficult to cut the leaves with the mandibles still.