Forgive me if this is an ignorant question, but I recently stumbled across the fact that two common nematodes (Steinernema feltiae and Steinernema carpocapsae, specifically) are very effective and aggressive parasites for insects of all kinds, including cat and dog fleas. Got me thinking, could nematode eggs be used as a viable all natural alternative to pesticides? If this parasite of parasites could live symbiotic with pets, it would seem more effective than most any other methods of pest control as the pet spreads the eggs around its environment. Primary flaw I see would be they're not accustomed to living on animals and would fall off within a few days, but nitenpyram also only lasts a few days and still requires further thorough treatment of the environment to prevent reinfection.