Unlike other tick control substances on the market, diatomaceous earth works via a purely mechanical method. Diatomaceous earth is composed of tiny, highly absorbent particles of silica that have rough, sharp edges. When ticks come into contact with diatomaceous earth, the fine silica particles bind to their exoskeleton, wearing away the outer layer. Once this protective outer layer is abraded away, the silica particles absorb the lipid oils and moisture from within the tick, fatally ...