Itch mites (e.g., scabies) and follicle mites (e.g., Demodex) affect humans and are medical concerns, not structural pest issues. TheGeneral Pest Management: Guide for Commercial Applicators - Category 7A(Chapter 7: Mites) advises that diagnosis and control should be done by a physician, as these mites require medical treatment (e.g., prescription creams). Option A (are poisonous) is incorrect, as they are not poisonous but cause irritation. Option C (residual pesticides) is not appropriate, as these are human parasites, not structural pests.