Melophagus ovinus, or the sheep ked, is a brown, hairy fly that resembles a tick. This wingless fly is about 4 to 6 mm long and has a small head; it is a fly from the family Hippoboscidae. They are blood-feeding parasites of sheep. The sheep ked feeds on the blood of its host by inserting its sharp mouthparts into capillaries beneath the skin. The legs of the sheep ked are very strong and tipped with claws. Sheep keds live their whole lives in the wool of sheep. They are most commonly found on the neck, shoulders, and underbelly of the host animal. Although they are often referred to as the “sheep tick”, sheep keds spend their entire lifecycle on their hosts, which is distinguishable from the characteristics of a true tick. Additionally, sheep keds have six legs, whereas true ticks have eight legs.