"Last week I was out for a five-day trip, and I never once detected anything crawling around me."
;) Tell you anything, Bob? (chuckle...)
Yeah permethrin works pretty good. Mostly, this is your face, since sleeping, you will be in your bag. A permethrin coated head net works. I personnaly don't bother...just slather on a bit of DEET and call it good. Scorpions (in the southern states or in desert areas, can be aoying, though.