Many animals have been found to have internal magnets. They use these
internal magnets for a variety of purposes. There is a bacterium that
uses its internal magnetic material to sense up and down so it can find
food on the bottom of its aquatic environment. Some birds are known to
navigate by using their ability to sense the Earths magnetic field.
Humans have extremely limited or no magnetic sense. I question, could
such a sense be surgically provided? Could a small implant be developed
that would allow a human to sense the Earths magnetic field?
If so, it would also raise a question of what this might do. Would there
be a down side as well as an up side? A person would probably have a
vastly improved sense of direction but, they might be prone to
experience unpleasant sensations when getting near unstable magnetic
fields or very strong fields such as an MRI machine.