Say goodbye to spider mites! SNS 217C? kills mites and their eggs. It is fully biodegradable and non-toxic to animals. How it works: Natural salts and fatty acids derived from rosemary extracts disrupt the insect cell structure. Cell contents then leak from damaged cells causing spider mites to dehydrate and die. SNS 217C? kills the spider mite eggs by coating them with an oily shield that disrupts the respiration to the egg; therefore no hatching will occur, they will just dry out.