Sloths are the cutest animals in the world. They are not just lazy – if that’s what you thought, they have amazing features and a fascinating lifestyle. So, in the following article you will find some of the best facts about these cute creatures.

Two-Toed and Three-Toed Sloths Aren’t All That Similar

The cute little babe pictured above is a two-toed sloth, of which there are two species belonging to the Megalonychidae family. The four species of three-toed sloths, on the other hand, are part of the Bradypodidae family.

The two groups are only distant relatives and have a few notable differences between them. While three-toed sloths are active in the daytime, two-toed sloths are nocturnal creatures. Three-toed sloths are also smaller and slower than their two-toed counterparts.

Both Have Three Toes, Though

The names used to distinguish the sloths are somewhat of a misnomer. Both have three toes on each hind limb. The real difference applies to the fingers on their forelimbs; one family has two claws, while the other has three. To avoid confusion, some groups—like The Sloth Conservation Foundation—have starting calling them two-fingered and three-fingered sloths.

They’re Related to the Extinct Giant Ground Sloth

Two-toed and three-toed sloths both evolved from giant ground sloths, the largest of which weighed several tons and stood about 12 feet tall. The animals went extinct about 10,000 years ago, likely due to hunting by early humans.

They Would Fail an Eye Exam

Sloths aren’t exactly known for their sharp senses, and this is especially true for their eyesight. A mama three-toed sloth can’t spot her own baby from 5 feet away, and combative male sloths have been observed trying to hit each other from a similar distance.

Scientists say a genetic mutation is to blame. Three-toed sloths are born without cone cells in their eyes, which are needed to detect colors. As a result, they see things in black and white, and in poorer resolution, too. They also have a hard time handling bright lights—not the best trait for a diurnal (daytime) creature to have.

Their “Laziness” Is a Survival Tactic

It’s no secret that sloths are slow. Their reaction time is about a quarter as fast as a human’s, and they move at a pace of 6 to 8 feet per minute. Indeed, three-toed sloths are the slowest animals on Earth, beating out other famously slow animals like giant tortoises and snails. When the animals were first documented in 18th-century scientific texts, they were harshly described as “the lowest form of existence.”

But their slowness is why they haven’t died out. Sloths largely subsist on leaves, and it can take up to a month for their four-part stomachs to digest a single meal. The leafy greens aren’t very nutritious, so they have to conserve as much energy as possible to survive—and that means moving less. As a bonus, their slow movements help them go unnoticed by predators that rely on sight to hunt down prey, like jaguars, ocelots, and harpy eagles.