When a petrel attacks them, emperor penguin chicks stand together against it. Watch out for a cameo from a particularly feisty Adelie penguin! Exclusive preview from #SpyInTheSnow, out in the UK December 30th. Learn more about Spy In The Snow: bbc.in/2Rcnc0K Subscribe to BBC Earth for more amazing animal videos - bit.ly/BBCEarthSub Watch more videos from BBC Earth: Planet Earth bit.ly/PlanetEarthPlaylist Blue Planet bit.ly/BluePlanetPlaylist Planet Earth II bit.ly/PlanetEarthIIPlaylist Planet Dinosaur bit.ly/PlanetDinoPlaylist Check out the other two channels in our BBC Earth network: BBC Earth Unplugged: bit.ly/BBCEarthUnplugged BBC Earth Lab: bit.ly/BBCEarthLabYouTubeChannel Spy In The Snow From penguins and parrots to polar bears and otters, for some animals the snow is the ultimate playground. Despite sub-zero temperatures they choose snowy conditions to find a mate, make a home and raise a family. In this one-o...