Herpetoculture is generally defined as the keeping and breeding of herptiles (meaning, amphibians and reptiles). It is not to be confused with the science of herpetology, although the two practices are not mutually exclusive. The large majority of herpetoculturists are amateurs who keep small numbers of animals at home as pets. However, there are many individuals throughout Europe and North America who maintain large numbers of individuals and often become seriously involved in propagation of certain species, often for the pet trade but also for conservation. The large number of herpetoculturists often contribute invaluable knowledge to the field of herpetology in both informal and formal ways, making the relationship similar to that between bird watchers and ornithologists.