Diatomaceous earth consists of fossilized remains of diatoms, a type of hard-shelled algae. It is used as a filtration aid, mild abrasive in products, including toothpaste, and is a mechanical insecticide. Bugs can not become immune because they are killed by physical action, not chemical.
What does mechanical insecticide mean?
Mechanical insecticide is like covering unwanted insects with broken glass; every time the insect moves, the diatomaceous earth (DE) cuts into the softer areas of the bug. Small holes are punched into the joints and the bug will dry out.
Also, bugs create a positive static electric charge on their shell that attracts these negatively charged particles to them and it sticks to them, ensuring their demise.
You can also protect your pets with diatomaceous earth. When lightly rubbed into their coats and dusted in your pet’s bedding area, food-grade diatomaceous earth is very effective against lice, mites, fleas, and ticks on dogs, cats, and birds. For an ear mites remedy for your pets, simply rub a pinch of DE onto the skin on both sides of the ear flaps daily for a month or so to kill existing and newly hatched mites. It works great as a deworming agent when added to their food or water.
Note: though this is very effective for killing pests, many veterinarians now do not recommend putting DE directly onto pets because of the risk of inhalation. It can be very effective sprinkled around your if fleas and ticks are a problem, however. There is little to no risk to pets if they roll in it.
Food-grade DE can be beneficial to humans. It is used to help clean the walls of blood vessels and lowers cholesterol if added to food or drink. A small amount of DE gets absorbed into the bloodstream as silica. One of the benefits of Silica is to help destroy bad fats. Everyone we know who takes diatomaceous earth has lowered their cholesterol by 40-50 points, and they are amazed at how their high blood pressure goes down.
The reason it is not harmful to humans when added to food is its size – 3 to 200 micrometers (Microns). Though diatomaceous earth is mostly harmless to humans, breathing in the dust can be dangerous, so be cautious when handling it.