Answer: Sloths

Sloths, tree-dwelling mammals found in South and Central America, are known for their slow movement; some of the slowest movement found in the animal kingdom. It’s precisely that slow movement that makes the sloth a mobile habitat for a variety of things including fungi, algae, and even more advanced organisms like moths.

Specifically, several members of the snout moth family have evolved to live exclusively in the fur of the sloths and have, in fact, turned the sloth into a sort of micro ecosystem. The moths feed off of algae and skin secretions and they leave the sloth only to deposit their eggs in sloth dung. Once the eggs hatch, the moths immediately seek out a new sloth host and live out their days on it. Sloths have been observed hosting upwards of 100 moths of several snout moth varieties and, in fact, it’s precisely this kind of heavy infestation of moths that led to the discovery of the sloth-moth relationship in the first place.

Back in 1907, sloth moths were discovered during the Smithsonian Biological Survey of the Panama Canal Zone. August Busck, curator of the moths and butterflies division at the National Museum of History, observed a particularly unlucky sloth fall from a tree and, upon hitting the ground, erupting in a flurry of moths. Further observations demonstrated that the moths actually lived full time on the sloths. Later research during 2013 even indicated that the presence of the moths changed the fur of the sloth to the sloth’s benefit, and hosting a large number of moths increased its chances of survival.