Flesh-eating buggers and what I learned

So weekend before last Tod and Rob came for a visit. Always welcome, always have room. Rob was given the sofa, a nice sofa from Pottery Barn, long enough to stretch out and purchased intentionally to provide an alternative sleeping area for those - rare, rare - times of domestic discontent and the more frequent needs of various visitors. But Tod, a repeat offender, I mean returning guest, was given the little guest room with a decent bed and a door you can shut, and a hell of a lot of my records which my wife wants me to get rid of.
After the first night, Tod mentions he's been bitten by something - and sure enough, he's got red blotches on his lovely neck and no doubt other equally lovely places on his skinny bod. (You should see him; lost 30 pounds, working out alongside Wendy now and pressing 250 w/ ease.) And just because we have a dog, okay, she scratches but shit, noone else, well, except our daughter, who happens to spend an hour or more a day in said room on unsaid computer, has had any skin problems.
We changed the sheets, took up the rug, vacuumed and hoped for the best, and sure enough, Tod was bitten no more.
What I learned: (thanks to Tod's research, so this fact is on him, not me - you think I have time for this crap?) Fleas don't need a "host" to survive in your home. They apparently lie dormant and then when you come clomping through a room or better yet, lie on a bed, they magically come to life and feed....in truth this solves a mystery and now I understand why denial really isn't a healthy concept.