Fleas hopping around on the floor - have treated the pet

[SleepFreeZone]

So I went too long between flea treatmenting the cat (my fault as had an awful lot going on with a pregnancy that ended in TFMR so took my eye off the ball). Never saw them on her but she was itching like mad and now she's not.

Only problem is every now and then I find one in the house. Just now there was a small one hopping on the bathroom floor that I drowned. Obviously they are in the carpet but we're not being bitten and the cat seems fine now. If I don't treat the carpet what happens next? I assume they need a good source and so if we're not being bitten might they just die?

No other animals in the house btw. Well apart from one cat, some spiders and some fleas 😬

Flea treat the cat. Hoover like crazy. Wash all the bedding. Get a flea spray for the carpets, cracks and crevices.

Flea collar that kills fleas for the cat. For bedding, sofas, carpets etc sprinkle liberally with salt - own brand table salt is fine.
Leave on the carpet for a couple of hours, then brush it up.
Vacuum like mad.
Empty vacuum cleaner outside then pop a flea collar in the vacuum cleaner.

They can complete their life cycle egg-larvae-pupa-flea in 3 weeks or they can sit about in the pupa stage for months, ready to jump out and bite you (or the cat). If you use an effective product on the cat they will jump on and be killed, but often not until they've bitten her. It's a bit mean not to do your best to eradicate them even if you are not being bitten. You need a household spray that contains permethrin and an insect growth regulator like S-methoprene e.g Indorex, Acclaim, Nuvan Staykill. They you need to fool the little buggers into hatching or they will sit in their pupa laughing at your puny efforts to nuke them. They hatch in response to warmth, humidity and vibration, so heating on, bowl of water on top of the radiator and Hoover first, then spray, concentrating around skirting boards and underneath heavy furniture that is not often moved. Any bedding goes in the machine on a hot wash. Then keep hoovering every couple of days. Keep up with treating the cat then any that you miss will be killed when they find her.
Sorry for your loss and hope your home is flea-free very soon

Sorry for your loss. I was in too much of a hurry to read your post properly. Good luck and best wishes.