Sloths are, indeed, fascinating creatures: The animal itself is appropriately named after one the seven deadly sins. Interestingly, the Spanish name for this creature is 'perezoso', ('lazy').

As earlier write-ups point out, a sloth typically spends almost all its time hanging upside-down in trees and spends 18-20 hours of each day "resting", (in the acting sense), or sleeping. When sloths do move around, it's at an excrutiating pace of about 6 feet per minute. Most of a sloth's "activity" goes on at night when it might move around in the tree tops. Sloth's even mate whilst hanging upside-down in the trees, since a journey down to the ground would waste precious energy.

The sloth is so conditioned to hanging in trees that the fur on its belly points the 'wrong' way so that rain can run off more easily. During the rainy season, its fur takes on a green-ish tinge due to algae which grows in its grooved hair.

In addition to algae, the slow-moving sloth often plays host to a great variety of insects - beetles, ticks, mites and even moths often live in the sloth's fur.

A sloth's infrequent trips to the ground are centred around foraging for food on the forest floor and a bi-weekly visit to the bathroom. This hour-long activity involves the sloth digging a hole with its tail before depositing its dung pellets and burying them. With all that activity, no wonder the sloth takes two weeks to rest between toilet breaks. During such an occurence, the moths living in the sloth's fetid fur take the opportunity to disembark and lay eggs in the freshly-layed faeces. Charming.

Given the huge amount of energy expended in descending from the tree-tops, spending an hour digging a hole and defecating before climbing back up again, many people have questioned why the sloth goes to such elaborate lengths. The answer, in my opinion, lies in the fact the sloth hangs upside-down in the trees.