A young Arctic wolf approaches Frozen Planet Cameraman Mark Smith during filming of the "Spring" episode. The wolf tries to steal some of Mark's belongings, but is easily scared off.

Frozen Planet represents the most extensive filming of the Antarctic interior ever attempted. Series Producer Vanessa Berlowitz explains how this was done from a twin engine airplane.

A southern sea lion tires of chasing gentoo penguins in the surf and attempts to run one down on the beach. Both champion swimmers, these two are anything but graceful on land.

In Arctic Canada, hundreds of beluga whales gather to shed their skin at the end of summer. Assistant Producer Elizabeth White sets up an underwater microphone to hear their squeaks and whistles.

Frozen Planet series producer Vanessa Berlowitz reveals what it's like for a woman to go to the bathroom in the poles. As challenging as it is normally, all modesty goes out the window when there are hungry polar bears about.

Frozen Planet series producer Vanessa Berlowitz explains how the amazing brinicle, or "icy finger of death," was filmed using time-lapse photography.

An older caribou bull is forced to fend off a herd of young males intent on stealing his mate. Will he stop to fight or keep up with the chase? He has to play his cards right, as the victor will be the new "boss."

The Arctic's woolly bear caterpillar freezes solid every winter, the natural antifreeze in its body keeping it from dying. It takes 14 years before it has eaten enough to become a moth.

The Chukchi, natives of the Arctic, risk life and limb to collect guillemot eggs from the side of a sheer cliff in the Arctic. Over the years, many men have fallen to their deaths doing this.

A large wolf comes trotting across kilometers of tundra to come face to face with a Frozen Planet cameraman. The wolf gets to within 10 meters, and the cameraman captures the encounter with a point-and-shoot.

Sealing in South Georgia Island nearly wiped out the Antarctic fur seal population, but today they are recovering. A researcher takes stock of how many fur seals there are in and around the island.

An Adelie penguin turns to a life of crime to build the perfect nest on Antarctica's Cape Crozier.

Adelie penguins live their whole lives near ice. Warming temperatures have meant less sea ice, and Adelie penguin numbers are in decline at their traditional colonies.

Stories of orcas working as a team to wash seals off of ice floews were legend when Frozen Planet went to Antarctica to film. After months of preparation and weeks of searching, legend became reality when the crew caught these images.

A Frozen Planet researcher discusses the life cycle of the Canadian Arctic's woolly bear caterpillar, which freezes solid every year for 14 years until it has enough energy to transform into a moth.

Growing up polar bear isn't all fun and games (although, that's part of it too). Polar bear cubs are forced to face some pretty big shocks in their first year in order to survive.