PARIS, June 12 — Pity the poor fly that lands on a Venus flytrap. When the insect touches hair-like structures on this remarkable carnivorous plant, its trap snaps shut, dooming...

Softening of the cells on the outermost suface of the trap lets the plant move at a breakneck pace.

Intricate tests show hair-trigger detection causes cells on outer surface of leaf to soften, prompting closure