You are in for some fun for the next two weeks to two months....
Fleas have a life cycle of about 2-3 weeks, from egg to egg.
You need to break the cycle.
Killing the fuckers that are alive is the starting point.
In addition to the following I suggest that you sprinkle Borax on the floor.
Borax has a diluted amount of Boric Acid which kills the fleas and flea larvae by cutting their shell and drying them out.
Shampoos and dips
A shampoo, or "flea bath" is a good first attack on fleas for the pet that has large numbers of fleas visible on its body. Cats can be difficult to bathe. It is important to know how to properly use the medicated shampoo to effectively rid your pet of fleas. It is also important to realize that a flea shampoo is not intended for lasting control. Many people are surprised when they see fleas and it was "only a week ago" that the pet had a flea bath. Shampoos are only effective for a day or less. They leave little residual chemical on the animal when properly used.
Flea dips are strong chemical rinses to rid animals not only of fleas, but mites and ticks as well. I do not recommend dips unless absolutely necessary, as in the case of a mite infestation. Dips last approximately 1-2 weeks. That is a lot of chemical residue to leave on an animal! Flea shampoos and dips are effective for adult fleas.
Flea collars
Flea collars work one of two ways - by emitting a toxic (to fleas, anyway) gas, and by being absorbed into the animal's subcutaneous fat layer. The toxic gas is usually only effective in the immediate area of the head and neck. This type of collar is best used in the vacuum cleaner bags to kill any fleas vacuumed up. The collars that absorb into the subcutaneous fat are much more effective. Ask your vet what collars they carry. Collars are not for all pets - particularly cats that roam outside.
Flea collars are effective for adult fleas. Some collars have an IGR, or Insect Growth Regulator, to prevent flea egg and flea larval development as well.
Flea powders and sprays
Flea powders and sprays offer short term (2-3 day) protection from fleas, and with some products, ticks and mites too. Powders and sprays have fallen out of favor recently with the newer spot-on treatments that are available.
Most flea powders and sprays are only effective for adult fleas, some offer additional flea protection by inhibiting flea egg and larval development (contain an IGR).
Spot-on treatments
Common brand names include: Advantagetm, Frontline®, and Bio-Spot® just to name a few. These products are applied between the shoulder blades of the pet, and typically last about one month.
Spot-on treatments are effective for adult fleas. Some include ingredients to inhibit the larva from emerging from the flea egg and some are active against larval development as well. Click on the product names above to learn more about each individual product from the manufacturer's web site.
Oral medications
Flea "pills", such as Program® and Sentinel® work by stopping the larva from emerging from the flea egg. Program® is also available as an injectable medication for cats. Fleas ingest the blood of animals on these medications, and the female fleas then lay eggs that are unable to hatch. They do NOT kill adult fleas. These medications are essential to break the flea life cycle and stop the flea problem when used in conjunction with flea adulticide treatments.
Flea control for your house and yard
Flea control doesn't stop after your pet has been taken care of! Only about 10% of the flea population (mainly the adults) are on your pet. The flea eggs, larvae, pupa, and the few adults that reside in the carpeting, bedding, and living areas make up approximately 90% of the flea population. Neglecting this population of fleas will ensure that the flea problem will continue and worsen over time.
Daily vacuuming - this is very important for picking up adults, eggs, larvae and pupae before they develop. Putting a flea collar in the vacuum bag and emptying the bag frequently are also important; otherwise, the fleas will hatch, develop, and leave the vacuum to re-infest the living quarters. See: Sharing a handy tip from 53CLASSIC.
Wash all bedding, clothing, and removable furniture covers.
Apply insecticide - over the counter fogger or by a professional exterminator, such as Orkin. Follow all instructions very carefully, remove all pets, people, and cover all food in the environment before applying insecticide, and make sure everything is dry and it is safe to return according to package directions. Take special precautions for pets and children - eating or putting items in their mouth, etc.