Phoresis
Phoresis or phoresy is a non-permanent, commensalistic interaction in which one organism (a phoront or phoretic) attaches itself to another (the host) solely for the purpose of travel. Phoresis has been observed directly in ticks and mites since the 18th century, and indirectly in fossils 320 million years old. It is not restricted to arthropods or animals; plants with seeds that disperse by attaching themselves to animals are also considered to be phoretic.
Phoresis is rooted in the Greek words phoras (bearing) and phor (thief). The term, originally defined in 1896 as a relationship in which the host acts as a vehicle for its passenger, clashed with other terminology being developed at the time, so constraints on the length of time, feeding, and ontogeny are now considered. Phoresis is used as a strategy for dispersal, seasonal migration, transport to new host/habitat, escaping ephemeral habitats, and reducing inbreeding depression. In addition to the benefits afforded to individuals and species, its presence can add to the ecological diversity and complexity of an ecosystem.