There are some ways that you can help control the fleas, but eradicating them can be a bit of a trial. There are herbal flea powders available, but these tend to contain exactly the same insecticides (pyrethrins) that a lot of the artificial ones do, as this is where they were discovered. If you regularly vacuum-clean your cat's bed, and everywhere it sleeps, or better yet bake its bed in a low oven, this will kill the resident fleas. You can also buy traps that work using a lightbulb.