Polyrhachis lamellidens

Found in primary forest above about 200 m in northern Taiwan, nesting in tree hollows. The queen is entirely metallic in sheen; workers are monomorphic with no major caste, with a metallic sheen on the head and gaster and a bright red thorax. Like other spiny ants it carries recurved spines, but most distinctive are the two backward-pointing spines shaped like fishing hooks. The species' most remarkable trait is that a new queen must become a parasite to found a colony: after mating, she finds workers of another Camponotus species out foraging and gets them to carry her back to their nest, where she sneaks in and kills the resident queen, then lays her own eggs and has the host carpenter ant workers raise her brood until the colony has been completely replaced.