The smaller of our native ticks, but that which perhaps poses the greatest risk to humans. Ixodes scapularis is teardrop shaped and relatively small, with a blackish dorsal shield over a reddish-brown body which fades to grey on engorged specimens. It is the primary transmitter of the Borrelia burgdoferi spirochete, the spiral-shaped bacteria that causes Lyme Disease, as well as being a disease vector for Babesiosis and Human Granulocytic Ehrlichiosis (HGE). Also known as the Blacklegged Tick.