The sixth sense: can humans detect the Earth’s magnetic field?

Scientists in California believe that internal compasses might have enabled our ancestors to navigate as some animals do today

Fruit flies do it. Tiny northern wheatears do it. Even salmon in the seas do it. All navigate using Earth's magnetic field.

In fact, hundreds of animals migrate this way, some over long distances. But one species has always been excluded from this electromagnetic orienteering club: Homo sapiens. Men and women show no evidence of possessing internal compasses, researchers have insisted.