A red fox pinpoints field mice buried deep beneath the snow, using his sensitive hearing and the magnetic field of the North Pole to plot his trajectory. For more North America, visit http://dsc.discovery.com/tv-shows/north-america/#mkcpgn=ytdsc1 Subscribe to Discovery: http://bit.ly/SubscribeDiscovery Join us on Facebook: https://www.facebook.com/Discovery Follow on Twitter: https://twitter.com/Discovery