It sounds like she is trying to kill any ticks or fleas that might have dropped off of an animal she transported in her vehicle? I suppose either approach could work, but the DE and a vacuum is perhaps less work than renting a steam cleaner. Just a guess.
DE does just sit there. The nature of the shape of the tiny fragments is that they scratch the exoskeleton of the insect and cause them to desiccate.
DE makes a very effective natural insecticide. The insecticidal quality of DE is due to its absorptive properties. When DE comes in contact with the insects, the powdery DE absorbs the body fluids causing death from dehydration. Said more simply, DE kills insects by drying â€˜em up. You will see how drying DE as if you handle it with bare hands.
The best way to apply the dust over a large area is with a light weight apparatus such as Dustinâ€™ Mizer, Spritzer or other similar blowers. Applying by hand can be done but wastes a lot of material and will dry your skin. To apply with water, mix Â¼ cup of DE in a gallon of water and apply to the lawn and/or shrubs where pest problems exist.
The wet spray method does work but only after the liquid has dried. Mix from 1-4 tablespoons DE per gallon of water and spray on the lawn, shrubs, tree trunks and building foundations. When the mixture dries, it has the same dehydrating powers as the original dry dust. When sprayed wet the material covers the foliage and other surfaces better than dusting dry, thus giving better insect control. It seems to last longer when applied wet but the dry application is usually more effective at killing insects quickly. DE has no insect killing power while it is wet.
Only pure feed-grade DE should be used to feed animals. There is no residual danger or contamination, in fact, DE is actually beneficial to the soil. Itâ€™s loaded with trace minerals. However, there are a few precautions. Diatomaceous earth is very dusty and can cause lung problems if breathed heavily, so when applying it dry always wear a good dust mask or stand up wind.
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