You can most effectively use borax for fleas if you have carpet in your home, but it may also be useful for homes without carpet as well. If you have carpet, you should sprinkle a small amount of borax on all areas of your carpet, concentrating on the areas where fleas seem to be most concentrated. Use a broom and brush the borax deep into the fibers of the carpet. Allow the borax to sit on the carpet for at least two days before vacuuming it up. You might have to use borax for fleas a few times a week for up to a couple of months before your fleas are completely gone.
If your home does not have carpet, you can still effectively use borax for fleas. You should sprinkle the borax all over your floors in the same manner you would use if you had carpet, but you won’t need to work the borax in with a broom. The only downside to doing this is that the white powder will be covering your floors, which might make it inconvenient for you to spend time in the rooms you are treating. For this reason, it might be a good idea to do rooms one at a time rather than treat your entire house with borax at once.
Whether you use borax for fleas on carpeted or hard floors, you will need to be somewhat careful about excess moisture. Borax absorbs moisture, and this absorption could make the substance very difficult to clean up, particularly if you have carpet. If you live in a climate with high levels of humidity, you might want to either not use borax on your floors or vacuum the borax up within 12 to 24 hours rather than letting it sit on your floors for two days. The longer the borax is on your floors, the more likely it will be to absorb excess moisture.
If you decide to use borax for fleas, you should be very careful to take your vacuum cleaner bag outside after you vacuum the borax up. It is likely that you will have vacuumed up thousands of fleas, both dead and alive, when you vacuum up the borax. The fleas that are alive can get out of your vacuum cleaner bag and back into your house. It might be a good idea to take the bag outside as soon as you’re done vacuuming and leave it there so you don’t have to worry about the fleas repopulating your home.