Therm-O-Rock Perlite is not an insect repellent, it supports root growth and keeps moisture, air and nutrients so plants can grow. This product will not treat for Red Mites aka Clover Mites. To treat Red Clover Mites, we recommend using an insecticide spray such as Bifen IT.  Please take a look at our Clover Mites Page for more information on Bifen IT and other recommended products. Outdoors: The best time to apply the spray is in the fall to prevent the movement of the mites to the house. Spraying should be done during the warmest part of the day when the mites are most active. Spray thoroughly around doors, windows, and foundations. Focus on the underside of the leaves of plants, bushes, and ornamentals as this is where Red Mites like to hide during the day. Granules such as Demand G Granules can also be applied in a 5 foot band next to the building foundation.