Extracted from quarries, amorphous diatomaceous earth (silicon dioxide) comprises extremely sharp fossils of microscopic marine algae. Its biocidal and insecticidal action are due to its highly abrasive and drying properties. And without habituation or side effect, it is useful against numbers of parasites and crawling insects. Diatomaceous earth should be used as indoor insecticide where animals use to spend their time (pillows, baskets, cages, etc.). Use with caution, reading the label before use is required.