Sorry, we couldn't find any results!
Please try a different filter above.
Over the last million years, our planet suffered a series of major ice-ages. Much of the northern hemisphere was covered in ice sheets several kilometres thick and creatures had no choice but to adapt or die
Never miss a Nat Geo moment
Join our curious community and you'll have access to some great features!
Personalised content reflecting your interests on the site
Watch exclusive videos before anyone else
Favourite content that you like or want to check out later
Free SMS and Email reminders so you never miss a show
Get notified when content that interests you is published
Share your photos on Snap! that could appear on TV
Share your thoughts and opinions on various matters
Receive a monthly newsletter with loads of great content