You might have to do a more thorough treatment to fix this problem, like treating the animals and the house
I am going through something similar right now. I was watching a neighbors cat while she was away, and a circumstance arose where I had to bring the cat into my house for an hour. Turns out, the cat has fleas. I had quarantined the cat in a spare bedroom. I carried it there, it never touched the floor of my house. Now, a few days later, there are fleas in most parts of the house. So they spread pretty easily.
not telling you what to do, but what I’m doing is I just gave my rabbit a dose of advantage II (that was leftover from last year, so I already had it handy). I’ve also just ordered a residual chemical from Amazon, to treat the carpets. I also ordered a fogger to treat all furniture with fabric etc at the same time. I will flea treat the house probably Saturday. Everybody has to be out of the house for a couple of hours while the chemicals are doing their job. Then, come back and open windows etc.
if you choose to treat your house follow label directions on the chemicals, very important. Also Advantage II can cause problems with some rabbits, I think Revolution is recommended these days as being safer. I just used the leftover Advantage because I know Ted can tolerate it.
good luck with your situation, however you deal with it