Food-Grade Diatomaceous Earth (DE) can be used for pest control and as a nutritional supplement. DE powder consists of crushed microscopic marine fossils. When insects contact DE, their exoskeleton is scratched, which leads to dehydration and death. DE also contains nutritional components and is a source of calcium, magnesium, titanium dioxide, gallium, sodium, and other trace minerals.
According to Health Canada “Applying a thin layer of Diatomaceous Earth (silicon dioxide) causes adult fleas to dry up when they crawl over it.”