Cleaning up a flea infestation in the home takes patience because for every flea found on an animal, there could be many more developing in the home. A spot-on insecticide will kill the fleas on the pet and in turn the pet itself will be a roving flea trap and mop up newly hatched fleas. The environment should be treated with a fogger or spray insecticide containing an insect growth regulator, such as pyriproxyfen or methoprene to kill eggs and pupae, which are quite resistant against insecticides. Frequent vacuuming is also helpful, but the vacuum bag must be disposed of immediately afterwards.
Flea “dirt” in the fur of a cat is actually excess blood from the host consumed by the adult flea and passed as feces
Diatomaceous earth can also be used as a home flea treatment in lieu of acetylcholinesterase inhibitory treatments or insecticides which carry with them a risk of poisoning for both humans and animals. However, Diatomaceous earth is at least potentially dangerous to pets and people when inhaled, so care in use is recommended. Application is effective on both the interior and exterior of one’s property, but the efficacy of Diatomaceous earth is diminished when introduced to water. Because Diatomaceous earth is commonly available in food grade quality, it is also possible to leave it exposed in areas typically vulnerable to fleas and other insects.
Dried pennyroyal has been suggested as a natural flea control, but is not recommended in homes with pets due to its high toxicity to mammals.
Borax is sold as a “Natural Laundry Booster” and can also be used as another home treatment for flea infestations. Borax contains sodium borate which kills fleas by dehydrating them, but its safety for pets is untested.
Using dehumidifiers with air conditioning and vacuuming all may interrupt the flea life cycle. Humidity is critical to flea survival. Eggs need relative humidity of at least 70–75% to hatch, and larvae need at least 50% humidity to survive. In humid areas, about 20% of the eggs survive to adulthood; in arid areas, less than 5% complete the cycle. Fleas thrive at higher temperatures, but need 70° to 90°F (21° to 32°C) to survive. Lower temperatures slow down or completely interrupt the flea life-cycle. A laboratory study done carried out showed that vacuuming catches about 96% of adult fleas. A combination of controlled humidity, temperature, and vacuuming should eliminate fleas from an environment. For a thorough deep clean, shampooing of the carpets is recommended Altering even one of these environmental factors may be enough to drastically lower and eliminate an infestation.