Around 99 million years ago, a juvenile cockroach met a hellish fate. It was snapped up by the jaws of a Cretaceous hell ant, a fierce predator with long, curving mandibles that swept up toward the top of the ant's head. Just moments later, the ant and roach were trapped in sticky sap that eventually turned to amber, providing scientists with a first glimpse of how the weird-faced ants trapped prey. The profile of a hell ant, with exaggerated upward-facing jaws that arc like the Grim Reaper's scythe, is unlike that of any ant alive today. Adding to the facial...