Because there is no 'S' in any of these! lol

Maybe Saint Patrick took a cruise and did his thing along the way ?!? :)

'Cos they cant get there. New Zealand, for instance, split off from Australia and Asia before snakes ever evolved. I guess fumigation of planes and ships take care of the few that might make the trip unlawfully.

Cause we are special? :P

Antartica probably wouldn't be the best place for a cold-blooded reptile to hang out.

Actually, it is not just those places. Those are just the biggest islands which are snake free. But there are some more. For instance, there are no native snakes in Hawaii. 1) "Now snakes are found in deserts, grasslands, forests, mountains, and even oceans virtually everywhere around the world. Everywhere except Ireland, New Zealand, Iceland, Greenland, and Antarctica, that is. One thing these few snake-less parts of the world have in common is that they are surrounded by water. New Zealand, for instance, split off from Australia and Asia before snakes ever evolved. So far, no serpent has successfully migrated across the open ocean to a new terrestrial home. As the world's oceans have risen and fallen over the millennia, land bridges have come and gone between Ireland, other parts of Great Britain, and the European mainland, allowing animals and early humans to cross. However, any snake that may have slithered it's way to Ireland would have turned into a popsicle when the ice ages hit. The most recent ice age began about three million years ago and continues into the present. Between warm periods like the current climate, glaciers have advanced and retreated more than 20 times, often completely blanketing Ireland with ice. Snakes, being cold-blooded animals, simply aren't able to survive in areas where the ground is frozen year round. Ireland thawed out for the last time only 15,000 years ago. Since then, 12 miles of icy-cold water in the Northern Channel have separated Ireland from neighboring Scotland, which does harbor a few species of snakes. There are no snakes in Ireland for the simple reason that they can't get there." Source and further information: http://nationalzoo.si.edu/Animals/ReptilesAmphibians/NewsEvents/irelandsnakes.cfm http://www.atheistnexus.org/profiles/blogs/saint-patrick-the-snake Further information: http://news.nationalgeographic.com/news/2008/03/080313-snakes-ireland.html 2) "They are found on every continent except Antarctica. No native snakes are found on the islands of Hawaii, Iceland, New Zealand and Ireland." Source and further information: http://www.animalhospitals-usa.com/reptiles/snakes.html "The great diversity of modern snakes appeared in the Paleocene, correlating with the adaptive radiation of mammals following the extinction of the non-avian dinosaurs. One of the more common groups today, the colubrids, became particularly diverse due to their preying on rodents, a mammal group that has been particularly successful. There are over 2,900 species of snakes ranging as far northward as the Arctic Circle in Scandinavia and southward through Australia and Tasmania. Snakes can be found on every continent (with the exception of Antarctica), dwelling 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 conspicuously absent such as Ireland, Iceland, and New Zealand." Source and further information: http://en.wikipedia.org/wiki/Snakes