A Hindu story goes thusly and if it is true, it'd have happened centuries before Saint Patrick. Parikshith, son of Abhimanyu, was killed by Thakshaka, the Serpent King. Parikishith's son, Janamejayan wanted to avenge his father's death. Helped by the absence of the Environmental Protection Agency in those days, he conducted a yaagam to kill all snakes. Thousands of the venomous reptiles fell into the yaagam's fire, and perished. A present-day Janamejayan would utter "justu missu" with a prefix for effect, to describe what followed. As Takshaka was about to be killed, Rishi Astika convinced Janamejayan to spare Takshaka and the serpent race.
According to Christian legend, Saint Patrick banished snakes from Ireland. The Saint and the men of his time could not have predicted that scientists with too much free time on their hands, and National Geographic would completely discredit his legend. Ice Age, geography and Charlie Sheen explain the absence of snakes in Ireland rather than any Christian miracle.
Scientists with too much free time on their hands have not disproved the Hindu legend, yet. Chances are, if not for a Hindu Ksathriya, Ireland would be crawling with snakes, and people everywhere would be playing Paramapadham (Snakes and Ladders) on Saint Patrick's Day instead of drinking in fake-Irish pubs named O'Nagarajan.
P.S: The close similarity between the names Patrick and Parikshith is not lost on the author.