structural:summarization, structural:scholar_edition
Distribution

There are about 3,900 species of snakes, ranging as far northward as the Arctic Circle in Scandinavia and southward through Australia. Snakes can be found on every continent except Antarctica, as well as in the sea, and as high as 16,000 feet (4,900 m) in the Himalayan Mountains of Asia. There are numerous islands from which snakes are absent, such as Ireland, Iceland, and New Zealand (although New Zealand's northern waters are infrequently visited by the yellow-bellied sea snake and the banded sea krait).