In treating the house, I would shake table salt into carpets, under sofa and chair cushions, animal bedding.

Supposedly the hatching larvae will ingest the salt and die of dehydration. Guess you can do the same out doors, if it is dry weather.

Don't know if it was really effective, or if only an old wives tale, but we never did have too much trouble with fleas.

I am extremely allergic to flea bites (get hives and try to stop breathing). So I knew when we had them in the house.