A small tick (about the size of a pinhead). It is this tick that can carry the Lyme disease causing organism (Borellia burgdorferi).

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.