Rhea and emu are both birds belonging to the RATITE family. Ratites are a group of flightless birds that include ostriches, kiwis, cassowaries, and rheas. Rheas are native to South America and are the largest BIRD in the RATITE family. Emus are native to Australia and are the second-largest BIRD in the RATITE family. Both birds have long legs and necks, and they are able to run quickly. They are also omnivorous, meaning they eat both plants and animals.