Antarctica's cold deserts have some of the least diverse fauna in the world. Terrestrial vertebrates are limited to sub-antarctic islands, and even then they are limited in number.[9] Antarctica, including the subantarctic islands, has no natural fully terrestrial mammals, reptiles, or amphibians. Human activity has however led to the introduction in some areas of foreign species, such as rats, mice, chickens, rabbits, cats, pigs, sheep, cattle, reindeer, and various fish.[9] Invertebrates, such as beetle species, have also been introduced.[10]