Ticks and mites are members of the same group. Mites are small in size and ticks are larger. Even for snake mites, checking under EVERY scale is unnecessary. Preferred location for any member of this group is the groove around the snake's eye. (Good hiding place with thin skin and lots of blood vessels.) If there are no mites or ticks there, chances are they are none elsewhere on the body.

I've seen at least two species of ticks on wild caught tropical snakes. The big grey ticks ranged from around 1/8 inch to around 3/4 of an inch long. The smaller brown ticks were 1/4 inch long or smaller. I never got a real identification of species from a professional tick man, though.

IMO, preferred removal method is to take hold of the tick with tweezers and gently pull backwards until the tick's mouth parts release. Then drop the tick in a bottle of alcohol. I took over 100 ticks off a boa constrictor that way back in the 1970s. Any insecticide that will kill snake mites will also kill ticks, but that doesn't get the mouth parts out of the snake's flesh. A wound from embedded mouth parts is likely to fester. However, an insecticide killed tick will not wander.

Different types of mites and ticks like different types of animals (or plants) as hosts. The nice part is that mites and ticks that like reptile blood generally think that mammal blood tastes terrible. So a reptile tick is unlikely to go for a human.

Your aunt means well. She may be generalizing from the wood ticks that get on people and suck blood. Those have gotten on me, and I did have to check myself over carefully to get rid of all of them. And sometimes I had to do it a second time. IMO, about all you can do is thank your aunt for her concern and tell her that you and your father have checked Dewey without finding any ticks. Good luck.