Updated: May 5, 2021
On average an adult flea lives for 2 months, and if your pet is host to mature fleas then they have become the nursery. There is roughly 5% of the population on your pet, the rest of is eggs and larvae that are spread around the house.
So unless you treat ALL of your pets as well as the environment it becomes very difficult.
Start with a reputable treatment for your pets. Don't waste your money on the stuff from the supermarket! We love and recommend (in no order) simparica, comfortis and advantage. The best way to decide what works for you is come and talk to us! That's what we are here for.
Wash their bedding in hot water, or with a flea shampoo.
As for the environment, vacuum or steam clean floors and you may have to use a surface spray. The outside of the yard should be mowed regularly if you have grass. Fleas like to have tall grass and they prefer the dark, so exposing the back yard to as much natural sunlight is helpful.
In areas they dog lays try placing wood chips like cedar. Its a natural insect repellant.
The bottom line is that its a multi faceted approach and you just can't treat one with out the other.