Most of the Skinks and Lizards I see with ticks seem to always have them in this location. My guess is that this is a soft spot and also the Skinks and Lizards can’t get to them to remove them.
I’m also guessing that Skinks will eat ticks.
Skinks are generally carnivorous and in particular insectivorous. Typical prey includes flies, crickets, grasshoppers, beetles, and caterpillars. Various species also eat earthworms, millipedes, snails, slugs, isopods, other lizards, and small rodents.