Ostriches (Struthio camelus) are large (up to about 3 meters in height) flightless birds in a relatively primitive group known as ratites. Other members of the group include rheas, emus and cassowaries. They have very long necks and legs, and are capable of running very fast (over 40 mph). Their feathers are not very developed, but some of them used to be very popular as ornaments in ladies' hats and such. Ostriches are large enough for a small human to ride them, and have been used in some areas of northern Africa or Arabia as racing mounts.
In popular mythology, the ostrich is famous for hiding its head in the sand at the first sign of danger. In reality, ostriches are far more likely to seriously injure threats with kicks from their powerful legs.
Ostriches are noted for communal nesting, where a number of females will dump their eggs into a single nest.