Isn't it odd that many of us don't have to work on Labor Day, but International Sloth Day is just another Wednesday? If you're moving slowly today, that's just fine: You're outpacing today's homepage subject, which spends 90% of its time scarcely moving a muscle.
All tree sloths alive today evolved from prehistoric giant ground sloths. The largest of these giant sloths, the Megatherium, measured up to 20 feet from head to tail.
