Ixodidae is a family of hard-bodied ticks that feed on the blood of various animals, including humans. Synonyms for Ixodidae include Ixodoidea, which is used interchangeably with Ixodidae family; hard ticks, to distinguish them from the soft ticks of the family Argasidae; and Acarina, which is a order of mites and ticks. Additionally, Ixodids are sometimes referred to as "ectoparasites" as they live externally on their hosts; "bloodsucking parasites," as they feed exclusively on blood; or simply "ticks," which refers to their small size and characteristic, distinctive shape. Despite the many synonyms for Ixodidae, they all refer to the same group of arthropods that can cause serious human and animal health problem if left untreated.