Hoots, chirps and the guttural wails of howler monkeys fill the humid, earthy air as we trek deeper. From floor to canopy, the tropical forest is crawling with creatures, and my guide, Robert Horan, ...

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 ...