Scientists studying penguins in the Antarctic have a problem - how to track down the birds.
The birds are pretty small, but they can be pretty messy too. They group together in colonies, and their poo leaves a reddy-brown stain on the ice.
In fact the stains can be so big they are visible from space - giving scientists a helping hand.
Thanks to the smelly stains, experts have found 38 emperor penguin colonies - 10 of which are new. That's a lot of poo!