Both the two-toed sloth and the three-toed sloth are nocturnal and move so slowly that algae has a chance to grow on them. Because of this, they often look grey-green, when in reality, they are a brown-grey color.
Sloths are rarely bothered by predators. Because they are slow-moving creatures and due to the way they hang in the trees with their arms and legs drawn up tightly around them, they remain hidden from dangerous predators such as jaguars. Sloths are arboreal, meaning they are tree dwelling and rarely make it down to the ground; this too keeps them safe.
Sloths are herbivores, eating things such as leaves, fruit and young twigs. Besides algae, they make a good home for other organisms such as cockroaches, fungi and beetles.
Today's sloths are direct descendants of giant sloths that used to live on the ground. These giant sloths were the size of elephants and posed a threat to animals living around them. They had thick joints and huge claws, meaning they were a formidable opponent for all predators. Many scientists, including paleontologists, believe humans were the cause of giant sloths becoming extinct.Learn more about Mammals