What is the general term used to describe parasites that live on the surface of their host?

The general term used to describe parasites that live on the surface of their host is "ectoparasites." Ectoparasites are organisms that attach to or live on the outer surface of their host, deriving nutrients and protection from their host while often causing harm. Common examples of ectoparasites include fleas, ticks, lice, and mites. These parasites can affect the health of their hosts by causing irritation, allergic reactions, or even transmitting diseases. Understanding ectoparasites is essential in fields such as veterinary medicine, entomology, and public health, as they can significantly impact both animal and human health.