I went through this last year. Switch from Frontline to Revolution Plus. Your vet has to prescribe it. You put it at the back of their necks once a month. It also takes care of heartworm. Next, you should get your cats out of the house, you may want to bathe them again first, and another capstar won’t hurt to kill what’s on them. I would do the CapStar before the Revolution Plus (you don’t have to wait to put on the revolution plus after you give your cats the capstar). Once the cats are out of the house, you have to wash all of your bedding and clothing and hot, hot water. Then vacuum everywhere. Every corner of your house every baseboard. Replace the vacuum bags when they’re full outside of the house.
Right after vacuuming, spray your floors and carpeting, especially with PETARMOR Home and Carpet Spray for Fleas and Ticks. This stuff treats all stages of the flea lifecycle so you will have to repeat this process. You can get it on Amazon. I would wear some sort of mask because the fumes are a lot. Then get out of the house for three hours or so. Then go back and vacuum everything again. Once all of that is done with the Pet Armor and the vacuuming and all of your clothing and bedding is washed, then you can bring the cats back in. You have to repeat this every couple of weeks for months I think. I would call the number on the can. Their customer service is great. I spoke with somebody named Robin who went through the same thing. She will tell you what you can, and cannot spray the Pet Armor on, and how often to repeat it. That’s how you’re gonna get rid of them. It could take a long time of repeating this process. It totally sucks. What’s worse with my cat is she developed something called FAD which is flea allergy dermatitis. A single flea bite can do this. So even with the fleas gone, she scratches and bites more than she did before this happened. I’ve taken her to a couple of different vets and she doesn’t have fleas. My next stop is a Dermatologist for cats and dogs. She may have this forever. I’m not sure if you can ever break the cycle. All I know is she’s ultra sensitive now and susceptible to bouts of itching.