Size of the Deer Tick

The size of the deer tick, or blacklegged tick, can vary depending on the sex of the tick and feeding state. Approximately the size of a sesame seed, a female adult deer tick measures about 2.7 mm in length. The males are smaller. These ticks are orangish brown in color but may change to be rust or brown-red in hue following feeding. The body becomes engorged after a meal and may expand considerably. Regardless, the deer tick’s body is approximately half as large as that of the common American dog tick.

Although small, deer ticks are capable of feeding upon large animals, including humans. Their small size can cause late detection. Early detection is important in order to reduce the chance of transmission of dangerous tick-borne diseases such as Lyme disease.