We quantified predation pressure on first instar nymphs of a stick insect in predator-exclusion experiments in the forest of Barro Colorado Island, Panamá. After considering intrinsic mortality (19%) and potential emigration (negligible), we estimated that 54 percent of the nymphs died due to predation in a two-week period. Predation on nymphs was highest at night and may explain the low abundance of Metriophasma diocles in the understory.