Sloths use their speed (or lack thereof) to their advantage:
they move so slowly that predators can't see them. This is a very
different tactic to that used by other jungle canopy dwellers, such
as monkeys, who attempt to use speed to escape their predators.
Sloths simply blend into their surroundings thanks to the algae
that grows on their fur. Their most feared predator, though, is the
harpy eagle, which still struggles to see the sloth even with its
exceptional eyesight. Good thing really because we don't fancy the
sloth's chances in a tete-a-tete.