Ectozoa is a general term used to refer to small, parasitic creatures that live on the outside of their hosts' bodies. These can include insects, arachnids, and crustaceans, among other creatures. While ectozoa is a specific scientific term for these creatures, there are a number of alternate synonyms that can also be used to describe them, including external parasites, ectoparasites, surface-dwelling parasites, and epizoic organisms. Each of these terms helps to describe the creature in a slightly different way, with some focusing on the fact that they live on the outside of their host while others highlight their parasitic nature. Regardless of the term used, however, ectozoa are important creatures to study for understanding their impact on the health of various species and ecosystems.