When treating a flea infestation in the home, vacuuming is a crucial part of treatment. All flooring should be thoroughly vacuumed before treatment as well as the days following your first application. A second treatment and more vacuuming should be done exactly 14 days after the first treatment for best results. For bad flea infestations, treatment may need to extend to 4 or more treatments. All pets and outdoor areas should be treated as well.