Chiggers live in a small number of places, I believe they dint like cold and prefer hotter climates Like Florida, Georgia, Etc. I don't think they are in the Merck because they live in suck limited areas, unlike lice and ticks that can be found almost everyplace.I even checked the Merck veterinary manual...nothing there relating to that term. You might want to call or check back with him or one of his assistants for further explanation.
Riki
Oh, and unlike regular roaches that scatter when you turn on the light, the three inch flying roaches either stand their ground or they come after you. There is nothing like walking into the bathroom in the middle of the night, still mostly asleep, only to turn on the light and see a giant pi##ed off roach glaring at you, puffing up and Hissing..