If there's one thing you know about sloths, it's that they're, well, slow.
But that doesn't mean they're boring.
In fact, sloths are one of the most extreme animals on the planet, and not just because they poop only once a week.
The Extreme Life of a Sloth
First of all, sloths really are extremely slow.
Their top speeds clock in at just 0.25 kilometers per hour, making them the slowest mammal on the planet.
According to zoologist Becky Cliffe, that's because, well, sloths can't really see.
Sixty million years ago, they lost the ability to see.
They went almost completely blind.
So, in the daytime, a sloth actually can't see anything, because it's too bright.