Ornate Sheep Tick Dermacentor marginatus

The genus to which this ornate tick belongs has achieved something remarkable: Dermacentor species are found natively on every continent except Australia—a global distribution that speaks to the genus's evolutionary success. As members of the hard tick family Ixodidae, these ticks have become worldwide travelers, adapting to diverse climates from tropical forests to temperate grasslands. Despite this cosmopolitan presence, most people rarely notice these tiny parasites even when they're nearby. The worldwide reach of Dermacentor makes these among the most geographically influential ticks on Earth, even if they remain largely invisible to us.