International Sloth Day is tomorrow! What a perfect time to brush up on your knowledge of these unique animals.

John, I want to celebrate by sharing some of my favorite facts about fascinating—and famously slow-moving—sloths.

Sloths depend on healthy Central and South American tropical forests. These solitary animals spend almost their entire lives in the tree canopy—eating leaves, sleeping, traveling along tree branches and vines, and trying to remain hidden from predators.

Have you heard about “two-toed” and “three-toed” sloths? The six species that make up the sloth family are grouped by the number of toes on the front limbs. Weighing up to seven pounds, the smallest one is the pygmy three-toed sloth, a critically endangered species found on only one island in Panama.

Now for the big question: can you guess why sloths are so slow?