The mystery migrations of birds of the world has long puzzled scientists, but understanding how it works may be one step closer to realisation.
Researchers found evidence of tiny iron balls in sensorys cells in the ear of birds. These neural, or hair, cells detect sound and gravity, and have been found in all types of birds, but not humans.
There has been much research into the use of iron by animals, but these balls had never previously been uncovered. Despite the finding the exact methods that allow birds to utilise the iron is yet to be discovered.