National Geographic : 2000 May
HOME SWEET HOME Chiseling an entry into the hollow stem of a Cecropia sapling, a Pachycondyla queen (below) seeks a place to start a new colony. Cecropia trees are common along rivers and near human settlements in tropical America; Macaranga trees are an ecological equivalent in Old World tropics. Ant workers, lured by sugary rewards along the margins of young Macaranga leaves (bottom left), patrol and protect this foliage, which is tasty-and vulnerable-to beetles and other herbivores. Macaranga also furnish their ant guardians with main courses, stashed in larders beneath purple stipules (near right). Inside, pearly globules of fat glisten, tasty as mini marshmallows (far right). Like peas in a pod, Pheidole ants live in tiny pockets on the leaves of Maieta shrubs (bottom right). One chamber usually serves as a nursery for ants and their brood, while the adjoining one contains ant refuse-a compost heap from which the shrub might absorb nutrients.