Standing up to 9 feet (2.7 meters) tall with lanky legs, massive
bodies, huge overbites and eyes the size of a child's fist, an
ostrich looks like an avian punch line [source: San Diego Zoo].
These birds are no laughing matter, though. They're the largest
birds alive, and they can kill a lion with one swift kick. The
ostrich is different from almost all other birds. They belong to
a family of birds called ratites, which includes emus and rheas
as well, and they are easy to tell apart from other winged
creatures. For one thing, these birds can't fly. As strange as
it seems for a bird to be flightless, it makes sense if you
consider flight as a way to escape predators. Ostriches don't
need that particular escape route because they can sprint at up
to 43 miles per hour (70 kph) and run long distances at more
than 30 mph (50 kph) [source: San Diego Zoo]. They're the
fastest animal on two legs. Their speed is even more impressive
when you consider they can weigh up to 400 pounds (181 kg)
[source: USDA]. While they