Trap-jaw ants (Odontomachus bauri) patrol a bed of moss and detritus on a tree trunk, jaws wide open. Disruptions to hairs on the inner side of their jaw trigger an explosively fast and powerful closure—check out the size of their head, which houses the muscles responsible for clamping their mandibles inward.
The closure is so powerful that the ant itself is sometimes launched off of the ground. In fact, they use the launch to escape predators.
Don’t worry, they’re unable to hurt humans.