Silicon dust adds residual killing power to your bed bug spray regimen and is an effective part of the bed bug killing team. Active spray ingredients usually kill a high percentage of bed bugs on contact. Many of the sprays will and should also kill the eggs. But only some of the ingredients provide long term residual killing power. That’s why many companies are adding silicon dust to their insect spray. Silicon dust gel mixes with the liquid and coats the surface being sprayed. The liquid evaporates, leaving a layer of silicon dust. Bed bugs in the area will pick up the dust just as humans pick up grains of sand when they walk down the beach. The dust penetrates the horny outer layer of their integument and dries them out from within. Because the powder coats the surface for a long time, the gel provides long term residual killing action.