Chiggers can really jack you up and make you physiologically ill, if you really get into them. Said hot bath needs additives like oatmeal or other soothing agents.
I am just about convinced that garlic keeps the horseflies and mosquitoes off of me. But not ticks. And not sure about chiggers. I take garlic supplements, and them horseflies and skeeters can be eating my buds alive, and they don't even bother me.