Diatomaceous earth

Diatomaceous earth used to treat a cat against fleas: very effective. Etching treatment (3 days away) and then once a week or every 10 days one puts a little. One can treat the safe environment with this product. Instructions provided.

And as rightly emphasizes a person in a comment, it is regrettable that this totally natural, therefore harmless to humans and the environment is not more developed.
It advises us all is smoke, the fogger and other highly toxic and carcinogenic insecticides while - as for everything - there are harmless and less expensive solutions!