It’s winter on a British meadow, and a red fox is on the prowl. The snow-covered ground masks the sight of its prey but the fox can still hear the telltale rustle of a mouse. It creeps forward slowly, listening intently with erect ears. Once it pinpoints the mouse’s location, it leaps into the air to surprise its prey with a strike from above. This pounce, known as ‘mousing’, is a common sight but there’s more to it than meets the eye. Jaroslav Červený has found that when red foxes pounce, they mostly jump in a north-easterly direction. He thinks that they’re using the Earth’s magnetic field to hunt.

Červený spent over two years studying wild red foxes in the