In biology, the term phoresis, also called phoresy, is an inter-species biological interaction in ecology and refers to a form of symbiosis where the symbiont, termed the phoront, is mechanically transported by its host. It is a type of commensalism; neither organism is physiologically dependent on the other.
Examples may be found in the arthropods associated with sloths. The coprophagous sloth moths such as Bradipodicola hahneli and Cryptoses choloepi, are unusual in that they are exclusively found inhabiting the fur of the sloths, mammals found in central and South America. The sloth provides transport to the moths whose females oviposit in the droppings of sloths, larvae feed on it and newly hatched moths move into the forest canopy in search of a new sloth host.