In the caterpillar-versus-plant fight, the winner might seem obvious. One side sits motionless in the sun, while the other feasts on it. But the tomato plant has a nefarious defense strategy. In some encounters with herbivores, it winds up relatively unscathed, while the caterpillars wind up eating each other.
Source: Gizmodo – Plants Turn Caterpillars Into Cannibals to Save Themselves