I'm so sorry that you've had such a hectic day. I've been in your situation before except that I only had 2 cats at the time. Mine are indoor only and still managed to get fleas. Since then I've been using advantage and it's worked so far. My new cat Cirrus is also semi-feral so I was worried about how to put the advantage on him. I just gave him a treat and while he was occupied I squirted it on him very fast. He didn't even realise it until later. He tried to lick it and started foaming at the mouth but I gave him some water and he was fine.

I wish they would come out with something that lasted for more than one month. I know they have the flea shot that lasts for about 3 or 6 months but it only sterilizes the fleas. I'm sure that in time it will happen some day.