Abstract: We review the biology of trap-jaw ants whose highly specialized mandibles generate extreme speeds and forces for predation and defense. Trap-jaw ants are characterized by elongated, power-amplified mandibles and use a combination of latches and springs to generate some of the fastest animal movements ever recorded. Remarkably, trap jaws have evolved at least four times in three subfamilies of ants. In this review, we discuss what is currently known about the evolution, morphology, kinematics, and behavior of trap-jaw ants, with special attention to the similarities and key differences among the independent lineages. We also highlight gaps in our knowledge and provide suggestions for future research on this notable group of ants.