Stephen Juan, an anthropologist from the University of Sydney, wrote that Caltech scientists discovered that humans possess crystals of magnetite in the ethmoid bone, just behind the nose:
Magnetite helps orientation and direction finding in animals. It no doubtingly helps migratory species migrate successfully by allowing them to draw upon the earth's magnetic fields. In the case, when it comes to humans, magnetite makes the ethmoid bone sensitive to the earth's magnetic field and helps one's sense of direction. Some have even suggested that this "compass" was helpful in human evolution as it made migration and hunting easier.