Answer: Pediculus humanus
Given the patient's history and location on the scalp, these arthropods are most likely P. h. capitis, a.k.a. head lice. As pointed out by Olivier and Lee, we have both a male and female louse here - a nice pair! You can identify the male by its terminal (caudal) projecting spike-like aedeagus (reproductive organ), while the female has a terminal inward-facing 'notch' representing the opening to the reproductive tract.