For a less-fun fact: tons and tons of bugs live in their fur. Sometimes literally thousands of moths, beetles, etc. are living in their fur. Some bug species are only found on sloths.

IIRC they also come down from their tree to poop once per week.

And the poop can be up to 3/4 of their total weight

Wait a minute.... that article says that the contents of their stomachs can be up to a third of their weight. Add 3/4 of their weight is poop, and that's more than 100% of each sloth being either digesting leaves or digested leaves.

I think that it probably goes like: 0/0, 30/0, 0/25, 30/25, 0/50, 30/50, 0/75, so that one in emptying into the other fast enough to avoid overslothing, assuming 5% goes to making the sloth fatter. This allows for a minimum "neither tummy nor turd" 20% sloth floor value.

If that were increased, we would instead see a series with smaller and smaller non-zero values for fullness as we approach maximum sloth fecalness.

Fecality factor?

Sloth stool ceiling.

I made a mistake. It's 1/3, but I think it's included in the "stomach's weight". Sorry

The mathematics works the same way as programming projects: when the task is 90% done you get to finish the remaining 90% of the work.

Why do they come down to poop?

They're not going to risk having it land on some poor unsuspecting sloth below them! That would be barbaric.