[jthacker]

While hemoglobin in blood has magnetic properties there’s no evidence that it leads to anyone being able to feel magnetic fields. At least one study has shown evidence for humans sensing magnetic fields but the author's do not make a case for blood being the biophysical mechanism https://authors.library.caltech.edu/90480/. The earths magnetic field is very weak and the force felt on our blood is even weaker.

It’s still a debate how animals sense the earths magnetic field. However, all theories rely on special adaptions and not on the extremely weak magnetic properties of blood.

[ncmncm]

Particles of magnetite in or between cells are a much more likely mechanism.

There are languages where grammar requires all directions are absolute, and even three-year-olds speaking those languages never get them wrong. I don't know of any studies to show they really are referenced to magnetic north, or are misled by artificial magnetic fields.

There is probably an easy PhD in showing such an effect.