Been there, done that with the diatomaceous earth, I buy it by the 10 lb bag for internal consumption (cats and humans), but it has done little to nothing when applied directly to the cats - other than piss them off and create lots of dust. Fleas don’t seem to mind it.
Instead of buying the flea traps w/night light, I just use pans of soapy water with a light hanging over it - same idea, and yes, it drowns any fleas who jump toward the light.
But they say that for all of the fleas you manage to catch, it’s only the tip of the iceberg, and I believe it!
I have used old collars sprayed with lavender oil but didn’t notice a difference except that the dogs smelled good. I have one that sneezes if she smells anything so I have to be careful with her.
My pups love to be flea combed especially if I dunk the combs in water/apple cider vinegar. It puts the ACV on their fur and they love the smell of it. I think dogs are more into the combing and brushing thing than cats are.
The strange thing is, my big dogs in the fenced yard 30 feet from the little dog’s yard didn’t have fleas. There must be a nest of them in the little dog’s yard that I need to find. The house wasn’t so bad that they were jumping on us and it wasn’t as bad as the yard but it was bad enough!
That's about right. This article on the flea life cycle says that at any given time in a given house about 50% of the fleas are eggs, about 35% are larvae (scrounging around for "organical material"), 10% are pupae in little flea cocoons, and 5% are adult fleas.
If you could get rid of all the adult fleas, 95% of the flea population would still be in the pipeline to flea adulthood.