A pseudoscorpion is a few millimetres of arachnid in a world of leaf litter and bark crevices, with no wings and no ballooning silk line of the kind spiderlings use. Its solution is to grab transport. An individual seizes the leg or hair of a larger arthropod with a chela and holds on, sometimes for hours, releasing when conditions look suitable.
The carriers are varied: crane flies, beetles, harvestmen and large flies are common. Some species can spin silk from glands in the chelicerae and will build a chamber around themselves on the host or at the destination, using the same silk for moulting and overwintering shelters.
Phoresy is transport, not parasitism; the pseudoscorpion does not feed on its carrier, though on some hosts it may eat the mites living there, which makes the relationship arguably beneficial. Whether hosts are selected actively or simply seized when available differs among species and is not well established for most.