Please explain how flea treatments work

[ProperLavs]

I have treated my cats with vet prescribed / strength flea drops. I had assumed this meant no fleas would be on my cats, but maybe I have misunderstood how these treatments work.
My cats still scratch all the time and I have found a number of fleas on them. The fleas are not as springy as usual.
Do treated cats still get fleas but the fleas soon die once they have bitten the cats?
Or are they supposed to repal and kill!
Do I need to contact the vet and complain?
Of course fleas are in the carpets again, but I think they jump off the cats rather than breed there.
I'm fed up with it.

It will take a little while, particularly if they weren't treated before. The fleas die when they get on the cat, but the eggs are pretty hardy, so you will have a period of new ones hatching and needing to be on the cat's to die.
Spray your carpets with Indoorex, or treat with diatomaceous earth to speed the process up.
What was the name of the flea treatment, fleas can be resistant to some of them.

Thanks, this the second month of them being treated. It's with primovox? So vet's own advocate.

If they were treated with fipronil it won’t work. Stronghold is a good flea treatment and works within 24 hours in my experience. Unless the house is infested as well, you shouldn’t be finding fleas on your cat after being treated.

The fleas can't die until after they bite the cats. They don't die instantly. Flea potion that comes with "household control" means that the fleas are also made sterile before they die, which cuts down on how many flea eggs can be laid before they die.

Nothing you can buy to spray at home kills the eggs & larvae (larvae need to eat adult flea poo & live in your floors -- but frequent vacuuming can remove some eggs-larvae-baby flea food). However, note, if you use Indorex: you need to leave it on floors a few days to kill fleas before you vacuum it all back up again.

So my cats could easily keep catching fleas from the rabbits and mice they catch? They are outside all the time and we are rural.

No, the fleas might get on them, but will die without breeding, so you won't get re-infestation.

But the cats will keep scratching and the odd on will jump off and bite us? Our carpets/ furniture don't have any. It's the cats. Good to know the fleas can't breed. The Ines I caught were round their tails and were a bit dopey.

Watching with interest - I treated my cat this week, I tried bob Martin (didn't work) frontline (still didn't bloody work) and finally on Friday advantage. Cat still scratching :-(

Bloody autocorrect . The fleas weren't round! They didn't leap off the comb as they had done before the cats were treated so hopefully they are dying.

Fleas & rodents have their own kind of fleas, I doubt those fleas live on cats. But cat fleas may be outside and brought in by your cats at any time, imagine any cats in the area who don't ever get treatment, their parasites will jump off into grass to lay eggs & look for a new host at next opportunity. That's why you need to give constant preventative treatment.

You also need to treat things like their bedding (and the whole house if its a flea infestation) with something like indorex. The fleas don't live on the cats but live in bedding and stuff.