Diagram of tick feeding. Tick A represents a superficial species, such as the American dog tick (Dermacentor variabilis). Tick B represents a more deeply attached species, such as the lone star tick (Amblyomma americanum). The leg bearing section is denoted the podosoma while the head region, the gnathosoma. When removal is attempted, the target region for contact with any removal instrument should be between the podosoma and gnathosoma at the basis capitulum.
shared here with permission of G. Needham
as found in the paper entitled "Evaluation of Three Commerical Tick Removal Tools" published in Wilderness and Environmental Medicine, 9, 137-142 (1998)
and on this webpage