Science Questions

Do humans navigate with tiny magnets?

My sense of direction’s absolutely appalling and I’m wondering about the deposits of iron in the brain. In the same way that bacteria make these miniature magnets we know other animals, including possibly us, also have them. How do they contribute to us having a sense of direction? How do they work? Richard Hawkins, New Zealand.

We put this question to Dr Sarah Staniland:

Sarah: Well, there definitely is some research that’s definitely true for human populations. There are these particles of magnetite which is the iron oxide and we definitely have these nanoparticles of iron oxide in our brains too. There is compelling evidence to say that they do indeed have a navigational side to them.

Chris: There’ve been researchers who put things like pigeons and bats in magnetic fields and managed to remagnetise their internal compass so they go off-course.

Sarah: That’s right

Chris: If you remagnetise your bacteria do they go off course?

Sarah: Yes, they do!

March 2008