If you've ever watched wildlife documentaries or flipped through photos of foxes, no doubt you've seen one leap when they're hunting a mouse, vole or other potential food source.

It's interesting and funny. The most photogenic images are in winter, with the gorgeous fox outlined against a blanket of snow. Stalking, listening with its oversized ears, cocking its head to pick up tell-tale signals from under the snow and then ...

Fling! Fwump! The fox disappears into the snow with its bushy tail and hind legs sticking out. Perhaps it nabs a meal or comes up empty. Such is the way of the hunter.

But why does a fox leap or pounce like that?

The actual act of hunting and leaping is called mousing. Some researchers believe foxes use the earth's magnetic field to better locate, hunt and kill their prey. Five researchers published their findings, titled "Directional preference may enhance hunting accuracy in foraging foxes," in the March 2011 issue of Biology Letters.

A portion of the abstract:

Foxes on the prowl tend to direct their jumps in a roughly north-eastern compass direction. When foxes are hunting in high vegetation and under snow cover, successful attacks are tightly clustered to the north, while attacks in other directions are largely unsuccessful. The direction of attacks was independent of time of day, season of the year, cloud cover and wind direction. We suggest that this directional preference represents a case of magnetic alignment and enhances the precision of hunting attacks.

Researchers have long believed that some animals, perhaps more than we realize, may use the earth's magnetic fields for navigation, migration or hunting.

Many believe birds' spring and autumn migration patterns are learned behavior, taught to young birds or they simply follow rivers and waterways. But the latter doesn't hold for their flights over the Gulf of Mexico or other seas. Research indicates their migrations in tune with earth's magnetic fields, and possibly other factors. Butterflies are believed to use the magnetic field, and researchers believe whales have substances in their eyes to help recognize the magnetic fields.

How foxes use the magnetic field for hunting remains an interesting part of our wild animal friends. Check out the video below of the fox mousing in winter.