There was an interesting article in last week’s New Scientist about the strange anatomy of the brain. It contained this quote:

No matter how bizarre a vertebrate is, it receives only three types of incoming sensory data: chemical (smell and taste), electromagnetic (light, and electric and magnetic fields) and movement (touch and sound).

I’d never quite looked at it this way before, but of course it is right. The only bit I don’t understand is what organ we use to detect electric and magnetic fields. Maybe we don’t. Maybe this is the preserve only of pigeons, which have been shown to have lodestone like sensors in their brains. Interesting though.