There are organic products, such as diatomaceous earth, that are very effective against fleas and also safe to use around cats.
You can also use diatomaceous earth; the kind you find in the garden center, not the kind for pools.
Or sprinkle diatomaceous earth around affected plants.
Diatomaceous earth exists at several places in Yezo.
In the shallow lakes and enclosed bays of the sea there began to be formed and still is in course of formation a deposit known by the name gyttja, characterized by the diatomaceous shells it contains.
Zelinkia and Philosyrtis are two slightly aberrant forms described by Giard from certain diatomaceous sands.
A diatomaceous earth in central Nebraska, occurring especially in the region of Loup, is a good polishing powder, and is used for packing steam pipes.