For International Sloth Day, learn about the scientific clues preserved in petrified poop Jack Tamisiea Several large chunks of fossilized poop that prehistoric ground sloths left in an Arizona cave ...

Defecating exposes sloths to predators on the jungle floor. An unexpected ally benefits, and returns the favor. A brown-throated three-toed sloth peers over a tree's buttress root while defecating on ...