My tenant, a lovely 84-year-old woman with a cat, called to tell me that she was being bitten by fleas in her apartment. At first, I didn’t believe her. However, upon entering the apartment, I could actually see the fleas jumping on the wooden floor. I told her she needed to get her cat the “good” flea medicine, as we live near the beach, and fleas are quite prevalent, especially in the summer. So the search was on for a nontoxic way to kill those fleas without harming her cat.
I googled everything I could think of. The results were varied: borax, but don’t use on wood floors, because the cat will lick its paws and be poisoned, and many other products purporting to kill fleas: bombs, sprays, and powders. But they all sounded ominous and toxic. Somewhere in my search I happened upon an article at Ecological Agriculture Projects, McGill University, Diotomaceous Earth: A Non Toxic Pesticide:
“Probably the most effective naturally occurring protective powder is diatomaceous earth. This is a geological deposit made up of the fossilized skeletons and tests of siliceous marine and fresh water organisms, particularly diatoms and other algae. These skeletons are made of hydrated amorphous silica or opal. When crushed, they break up into tiny pieces of glass” (so tiny that the material feels like talcum powder). This is easily picked up by the hairy bodies of most insects, whereupon it scratches through their protective wax layers; and they also absorb some of this material, the result being that the insects lose water, dry up and die. Further protection is provided by the powder’s property of repelling many insects. A similar principle probably accounts for the fact that birds frequently take dust baths, presumably to rid themselves of parasites.”
There are two kinds of diatomaceous earth. One is used for swimming pools and is too fine for the job of pest control. Look for the garden variety, which is less fine. I bought a box at B&B Hardware, brought it home and sprinkled the floor with it. The fleas were gone in two days. Diotomaceous earth is also excellent in the garden. It will control slugs, fleas, and even flies. So if you are looking for an environmentally safe solution to garden pests, try Diatomaceous Earth. It worked for me.