What parts of the body do ticks prefer to bite?

In their study, “Human attachment site preferences of ticks parasitizing in New York,” Hart and colleagues describe which body parts black-legged and lone star ticks prefer to bite.¹ They collected ticks, submitted between April and December 2020 from individuals living in New York State, along with online questionnaires indicating where the tick was attached.

They examined the biting behavior of 3 species of ticks: Ixodes scapularis (deer or black-legged tick), Amblyomma americanum (lone star tick), and Dermacentor variabilis (American dog tick).

A deer tick, which can transmit Lyme disease, is not so fussy about where it bites.

The team found, that the “I. scapularis is less specific in its preferential attachment sites,” than the lone star tick. “However, the life stage and infection status impact the tick’s attachment site.”

Deer ticks: Body parts it prefers to bite

The black-legged tick does not seem to prefer a specific body area. “Ixodes scapularis is primarily found on the central trunk, including the groin/pelvic region, the abdomen, the thoracic region, and the head/neck,” the authors write.

However, the tick’s life stage and infection status can impact where it attaches on the body.

The immature life stages prefer the limbs, while I. scapularis infected with B. burgdorferi prefer to bite the central trunk versus the limbs.

In contrast, the lone star tick prefers to attach to the lower midsection, upper legs, and groin.

“More adult [I. scapularis] ticks were found in the thoracic/abdominal region of the body, while nymphs were more often attached to the arms and legs,” the authors write.

Infected ticks: Biting behavior

Ixodes scapularis ticks were screened for several pathogens.

Anaplasma phagocytophilum, B. microti, and other pathogens (DTV and B. miyamotoi) did not influence which body area the ticks chose to feed on.

“Many tick samples were found to be carrying multiple pathogens.”

However, if the tick was infected with B. burgdorferi, there was a significant change in the distribution of tick bites – more bites in the midsection and fewer on the arms, legs and head.

If the deer tick is infected with B. burgdorferi, it prefers to bite the central trunk versus the limbs.

“Bacterial and protozoal agents transmitted by I. scapularis take several hours for an infectious dose to be transmitted,” the authors point out.

“Therefore, prompt detection and removal of ticks is important for preventing tick-borne disease.”

Lone star ticks: Bite quickly

The lone star tick can transmit Ehrlichia chafeensis and E. ewingii.

“The [lone star tick] is also associated with Southern Tick-Borne Rash Associated Illness (STARI), a disease of unknown etiology that has previously been observed in New York” and with the Alpha-gal syndrome or red meat allergy, the authors explain.

With all life stages, the lone star tick was most often found in the thigh/groin/pelvic region.

This tick species tends to bite quickly, instead of ascending to higher regions of the body, like the torso or head.

The authors point out, the information gathered from their study can be helpful in protecting the public from tick-borne diseases. Educating individuals about the body parts most likely to have ticks attached can potentially reduce the transmission of tick-borne pathogens.

Authors Conclude:

• Body regions where tick bites human vary depending on the tick species and life stage, and clothing worn by the host.
• The lone star tick prefers attaching to the thighs, groin, and abdomen.
• “Ixodes scapularis was found across the body, although it showed a significant life stage difference with adults preferring the head, midsection, and groin, while nymphs/larvae preferred the extremities.”
• “Infection with Borrelia burgdorferi resulted in a significant change in attachment site.”