When your doctor orders three mammograms and two sonograms, and then waits one nano-beat too long before saying “biopsy,” go see a sloth. Earlier this month, that’s what I did, at the National ...

This silence helps them avoid attracting attention from predators. In fact, many researchers studying these species rely on visual tracking rather than sound because these creatures are so difficult ...

While humans wouldn’t be very happy to find that organisms were growing on their skin, particularly fungi, algae, and insects, it works out pretty well for sloths. Sloths may be hosting entire ...