Sorry you have had to wait so long for an answer. I hope I can answer some of your concerns. I am wondering how long ago you applied the frontline and do you have other animals in your house?
I would like you to do an experiment- take a fine tooth comb- a flea comb would be great, and comb your cat many times over the neck, back, and just in front of the tail.
Hold the comb over a white paper towel and clean the hair and debris out of the comb and onto the paper towel. If you have any other animals- do the same thing for them.Once you have collected this material on the paper towel you need to get it moist, a spray bottle with water is best but you can just sprinkle water over it. Now go away for 10minutes. When you go back and look at the damp paper towel- tell me what you see.
I look forward to your answers.
I put the Frontline on the cat about 3 weeks ago. I must say the Frontline is about 4 years old - may not be very effective. I followed your instructions, and Little black specks turned red on the wet towel after a few minutes. Our lab is regularly treated with Frontline and has no black specks. I rarely use Frontline on the cat. I see no signs of fleas now. I will await your answer.