Summary: The big-headed ant (Pheidole megacephala) is considered one of the world's worst invasive ant species. As the name implies, its colonies include soldier ants with disproportionately large heads. Their giant, muscle-bound noggins power their biting parts, the mandibles, which they use to attack other ants and cut up prey. In a new study, University of Illinois researchers report that big-headed ant colonies produce larger soldiers when they encounter other ants that know how to fight back.
