How odd...
Chester probably eats things that fleas don't like, if he's an outside cat. Annie may just have a more tender skin that fleas prefer.
If I'm in a house with a flea population, I will get bites on my legs, even if I'm only in the house a short while. Other people are not bothered by them.
Dunno. Could be. I know we put out catfood and water for them on a daily basis. I even have to chase off the occassional raccon or possum. Tempted to pay the tax/registration and get a silencer/suppressor for my bolt action .22LR. I've never tried possum stew before...