hi smilingcat, thanks for the informative post.
I do comb cats, but have not found a single flea on a cat this season.

this is what i figured out:

before i went on vacation i changed the sheets (and slept on them the night before we left) then i made the bed and put two more sheets on top.

I think i sealed the nasty little varmints into the bed!! so when i climbed back into the bed after my vacation, they were famished!!

the day after we returned, of course, i washed all the bedding but now there were fleas prob. around the bed.
combed all cats again. (heck, they like it)

I sprayed some Raid for Fleas under the bed but did not want to poison myself or the cats so i stripped the bed again and

i ironed the mattress
then put the bottom sheet on.
ironed it.
put the top sheet on
ironed it
put the blanket on
ironed it.

and last night i slept for 5 hours straight.

even fleas can't survive an iron set on HIGH.