It’s called magnetoreception, and it refers to the ability to perceive magnetic fields. Several animals use it to find their way over long distances by aligning themselves with the Earth’s magnetic field. Sea turtles. honeybees, spiny lobsters, dolphins, migratory birds, and more all have a magnetic compass which allows them to use the information that’s coded into magnetic fields. We know little beyond that, however. How they use them, how they sense them, and what information they are getting from them remains up for speculation. For all we know, these magnetic fields could be used for much more than navigation for certain species.
According to Joe Kirschvink, the geophysicist at the California Institute of Technology who is currently testing humans for a magnetic sense, “it’s part of our evolutionary history. Magnetoreception may be the primal sense.” (...)
A recent study published by Kirschvink in the journal Nature Communications suggests that a protein in the human retina, when placed into fruit flies, has the ability to detect magnetic fields. The research claims that it can serve as a magneto sensor, but whether or not humans actually use it in this way is unknown.
(...) In one of Kirschvink’s recent experiment, a rotating magnetic field was passed through study participants while their brainwaves were measured. He discovered that when the magnetic field was rotated counterclockwise, certain neurons responded to this change which, in turn, generated a spike in electrical activity. This suggests a possible magnetic sense in humans.