I have been using Advantage ll for dogs on my cats for 4 years. This is based on their weight and it has always worked great. Recently I have noticed that it isn't working anymore. I found your website and decided to try Frontline ll for dogs on my cats. Its not working at all and I now have a flea infestation in my home I do not want to fumigate my home until I find something that will work on my cats. Does anyone have any ideas of what i can try on them now. And how long is Frontline ll supposed to work on my cats? Monthly treatments?