I had a flea issues once. Poor Ann had to wait a year for her kits because I wouldn't risk selling with any chance of fleas.
My problem was from my dogs and cats.
Cat fleas stay on the animal for the entire life cycle. Dog fleas jump off to lay eggs around the house and yard.
I had both fleas and so did the buns.
My buns at that time were in the house in a room off the kitchen.
First thing I learned was to get the rabbits out of the infested house. I tried for months and months to get rid of the fleas to no avail.
Fleas dont really care for buns but when there is an infestation they will suck anyone's blood.
I moved the buns to my rabbitry outside. Its attached to the house but not in the house.
I dusted each rabbit with food grade DE. DE irritates animal and peoples lungs, be careful with the dust and use it outside.
I treated the floor of the rabbitry with sevin dust and tossed cedar chips on top of that. My rabbitry is very ventilated as it has spaced planking for walls. So a fine layer of cedar on the floor doesnt hurt the animals.
In no time the fleas were gone from the buns, days.
My house, I got that spray stuff from the vet that breaks the cycle and then I went to frontline for the dogs and cats.
It tooks several more months to get the house flea free but now we are totally flea free and stay that way.
For prevention my dogs and cats get frontline all through the warm season.
The rabbitry I always sprinkle a little sevin dust on the rabbitry floor along the walls creating a perimeter.
I toss some pine shavings over that. The couple of pet chickens that live in there with the buns mix it all up.
I have a dirt floor.
The sevin keeps fleas from making house in the rabbitry and also works to prevent other nasties like lice.
My rabbits are in all wire cages so no bedding issues.