When fleas are in their protected cocoon stage, they can stay like this for a very long time. They only emerge out of it when they believe that a food source is near by.
To speed up this process and
shorten the flea life cycle, vacuuming is an easy, cheap, and quick way to fool these pests into leaving their protected space.
The vibrations from vacuuming can fool the pupae into believing that there is a nearby food source, and they will emerge from their protected cocoons in search of it.
Once they emerge, they are either then killed off by being sucked into the vacuum, or by biting into your protected dog.
Many people say to change the vacuum cleaner bag after you vacuum, so the fleas can not escape from it.
I don't do this. Not only is that expensive to do, but to me, it's a wasted effort.
It is much cheaper to simply purchase some flea powder, dump a small pile on the carpet and then vacuum that up, before you do the rest of your vacuuming.
Then you only need to replace the vacuum bag when it is full, as you normally would.
As for vacuuming, you can do this as often or as little, as you see fit.
By simply combining the steps of protecting your dog and vacuuming, you can live in your house without ever worrying about getting a flea bite!