How do Racing Pigeons find their way home?

How do racing pigeons find their way home? No one knows for sure. Research at Cornell and the University of Pittsburgh indicate that pigeons may have multiple facilities allowing them to determine the correct direction of home. There is little doubt that the sun is the primary orientation clue used by homing pigeons, but there have been experiments which have developed night flying pigeons, thus showing that the sun is not the only available orientation reference. Some scientists believe that pigeons also perceive the earth's magnetic field and utilize it for finding their way home. Other scientists have opined that pigeons may orient through a sense of smell or even low frequency sound via their hearing. Research is still going on at several universities trying to learn the secret of this bird's ability to navigate distances of 1,000 miles or more to return to its owner's backyard loft. But as far as breeders are concerned, the only way to discover if a bird possesses the required homing instinct, as well as athletic ability to do so quickly, is to race them.

* http://members.aol.com/rpdmag/racingpigeondigest/pgnintro.htmthey have there own little way of navigating around they no by remembering what certain places look like and so they know there way back its like thy have there own sat nav in there heads