Earth Matters

A frozen river of poo is sliding down Denali

Why Africa is building a Great Green Wall

13 must-see trees around the world

What's the difference between black rhinos and white rhinos?

Meet the world's 8 tallest land animals

How to kill mosquitoes naturally

Time-lapse captures bizarre beauty of Norway's floating islands

The odd reason flamingos are flocking to Mumbai

NASA's 'Mars Helicopter' aces tests ahead of historic flight

Dolphins found suffering from Alzheimer's

Trees are the not-so-secret weapon in keeping cities cool

How mosquitoes sniff out human sweat