If you're ever lost in a pasture, just follow the cows home.

Scientists have discovered that cattle have built in compasses aligning them with the Earth's magnetic field.

Any time you see a group of cows in a field, the majority of them are likely to be lined up in a north-south direction.

Researchers at the University of Germany looked at thousands of aerial and satellite photos on Google Earth.  They compared cattle in Britain, Ireland, India and the USA with a herd of 3,000 deer in the Czech Republic.

Experts had noticed the deer tended to face north when resting or grazing, and the images of the cows showed the same behavior.