According to a legend, St. Patrick used the power of his faith to drive all the snakes from Ireland into the sea. Though it sounds impressive, it’s not exactly what happened.
In fact, Ireland has never really had snakes, and it’s not the only country in the world without the legless reptiles. The same goes for New Zealand, Hawaii, Greenland, and Iceland, and the reason is simple: they are all islands.
Ireland was once part of a larger landmass. Around 10,000 years ago when the Ice Age ended, the glaciers started to melt, which resulted in Ireland separating from the land and becoming an island. Snakes did not make it to the island and they didn’t get a chance to make it across later.