Catching a delectable insect may be all in a day’s work for a Venus flytrap, but researchers have spent years wondering about the chemistry this predatory plant uses to snag its dinner. A team led by Minoru Ueda of Japan’s Tohoku University has now discovered that the plant uses a pair of chemicals to ensure that potential prey is indeed ruffling the trigger hairs in its mouth so that it doesn’t expend energy to clamp shut in vain (ChemBioChem, DOI: 10.1002/cbic.201000392). For instance, when a single hair is tweaked, the plant’s mouth remains open. But if several hairs are ruffled, the plant snaps closed. Ueda and coworkers found that two chemicals are secreted as each hair is perturbed: β-d-glucopyranosyl-12-hydroxyjasmonic acid (shown) and a large, carbohydrate-rich molecule that remains unidentified. The researchers propose that when enough of the two molecules accumulate, ion channels in the plant open, stimulating an action potential. The plant, certain that it is indeed mealtime, then shuts its trap.