Hippos can’t technically swim The perfect combination of buoyancy and bone density allows them to “fly” thorough water at speeds of 5mph, (8 kph) propelling themselves using intermittent ground contact, like astronauts on a moon walk.

Hippos can’t technically swim The perfect combination of buoyancy and bone density allows them to “fly” thorough water at speeds of 5mph, (8 kph) propelling themselves using intermittent ground contact, like astronauts on a moon walk.