Yes, kids, the Earth is a giant magnet, which is why compasses work.
But more than that, it's been a scientific fact that birds and bees navigate using the Earth's magnetic fields, which run from the South to the Earth's magnetic North. It's how those flying beasties migrate, or find their hives and nests.
And recently, it's been discovered that large mammals — cows, in particular — may also have a magnetic sense. A recent German study using Google Earth images reports that grazing cows tend too line up north-south in accordance with the magnetic field (unless they are "confused" by nearby heavy-duty power lines).
That said, it's been an old wive's tale that humans can detect magnetic fields as well, and that humans' sleep will improve if they align themselves north-south along the magnetic field. This has led to a small cottege industry of magnetic mattress pads which, some claim, can not only enhance sleep, but cure all kinds of physical ailments.
Is it real, or bogus? Can human sleep/health be improved by positioning our beds in a north-south direction?
Well, the science isn't there yet. On the other hand, it wasn't there a year ago for cows, and now we know better.
So… maybe it's worth rearranging your bedroom. You never know.