Please advise with flea control

My two kitties are free of fleas, but my daughter's Chester isn't. She is using Frontline and asked me to get some advice from you all on whether there is a natural spray or substance for the areas in which Chester sleeps. She hates to use all that stuff with the chemicals in it. Chester has never been an outdoor kitty. She's had him since he was 2 1/2 wks. old. However she feeds some outdoor feral kitties on the porch and Chester sits by the screen door looking out at them. I read that fleas can get thru the screen. My two kitties were recently in the hospital for a few days due to recalled food and I'm really watching them and hoping they didn't bring any fleas, worms, etc.
home with them. Thanks for any advice on flea control in the house.

We humans can actually bring in fleas on our clothing. If she is using Frontline and doing it every month, then eventually she'll be rid of the fleas, but in the meantime, a good thing to get is diatomaceous earth (not sure of spelling). Just sprinkle some in the carpeting and it will kill the fleas and also the hatchlings. I personally have never had much luck with chemical sprays and such that I bought or got from the vet and they could possibley be toxic to the kitties.

She can try diatomaceous earth:

http://www.holisticat.com/fleas.html
http://www.critterchat.net/diearth.htm

There's an echo in here!

I think I must have been pulling links as you were posting.