We had a flea problem this summer that just exploded. It seemed to center around the dog and one cat. We use Frontline. I've heard on the news and at my vet's to put it on every 3 weeks because it does seem like the fleas are getting used to it. Once a month in winter is fine, though.

I did some research because I really wanted to stop the cycle of fleas. I don't like to use chemicals either, but this was desperate. We went to the feed store and bought a product with Nylar in it, which is an insect growth retardant. It kills the larvae and the eggs. We also used a product called Viper which kills adult fleas. We vacuumed first, then we used the Viper on all parts of the inside of our house. Then we used both the Viper and the Nylar on the yard where the animals mostly go. There was one particular place under the azaleas that the dog and one cat liked to dig a hole and sleep. We sprayed it and then covered it with a lot of mulch that they don't like to dig in.

Then we dipped both cats and the dog in a flea dip that ALSO contained the insect growth retardant, and then they all got Frontlined again. While I was spraying the house, I moved the cats to an outbuilding and sent the dog packing to my Dad's. When the came back, I knew they were flea free and the yard was flea free.

The cats did not suffer from being dipped and having the Frontline reapplied. Well, they THOUGHT they were suffering, judging from the looks on their faces! I dipped them outside in the kiddie pool so they could run away when it was over and not trash the house.

Also, Frontline will eat the finish off of leather upholstery (I found out the hard way on my new leather sofa). A month or two later and we're flea free, but we did apply the chemicals twice in order to catch all the eggs/larvae. (The IGR is supposed to be good for about 7 months.)

Here's the link to the information I found.
http://www.tulsamastergardeners.org/...as_ticks.shtml
http://insects.tamu.edu/extension/bu...uc/uc-034.html

Karen