blood-sucking acarid parasites of the suborder ixodedes, superfamily ixodoidea. The ticks are larger than their relatives, the mites. They penetrate the skin of their host by means of highly specialised, hooked mouth parts and feed on its blood. Many species can live for long periods, well over a year, between feedings. Ticks attack all groups of terrestrial vertebrates. In man they are responsible for many tick-borne diseases, including the transmission of rocky mountain spotted fever, tularaemia, babesiosis, and relapsing fever.