The Order Rheiformes consists of large, flightless birds known as rheas, native to South America. These birds resemble ostriches and emus, with long legs and necks adapted for running at high speeds to escape predators. Rheas are herbivorous or omnivorous, feeding on plants, seeds, and small animals. They live in open grasslands and pampas, often forming small flocks outside the breeding season. Socially, males take a prominent role in nesting and chick-rearing, incubating eggs from multiple females in a single communal nest. Rheiformes play an important role in their ecosystems by aiding in seed dispersal and serving as prey for large predators.