WHEN the mother-of-pearl caterpillar is confronted by a predator, it
flings itself backwards at 39 times its walking speed, completing half a dozen
somersaults on the way.
The reclusive Pleurotya ruralis spends most of its life rolled up in
a nettle leaf, and as a result has not developed any standard caterpillar
defences, such as hairiness or tasting horrible. So on the rare occasions when
it ventures out of its leaf in search of pastures new, it needs to make a quick
getaway when a predator appears. 鈥淪huffling around like a normal caterpillar
won鈥檛 do,鈥� says John Brackenbury of the University of Cambridge. He used
high-speed video equipment to study the caterpillar鈥檚 technique, which he
reports in this week鈥檚 Nature(vol 390, p 453).