Africa's tallest tree discovered towering on continent's highest mountain

Photographer snaps rare shot of 'ghost rainbow'

Ant colonies discovered farming their own fruit crops

Mysterious 'earthquake lights' captured over New Zealand

5 invasive species that may have won the war

3 reasons why you shouldn't lose hope

Alaska's bizarre 'Ice Monster' has everyone stumped

This featherless penguin wears a custom wetsuit

5 facts about Vieques' bioluminescent Mosquito Bay

Iconic Milwaukee conservatory ranks among America's most endangered places

A 'hidden' forest in the shape of a Celtic cross has emerged in Ireland

Only 1 specimen of this 414-legged creature has ever been found