The first mice are said to have been born in Ireland at the hands of a young maid who was a follower of St. Colmcille. Colmcille called out for Jesus to aid him in feeding the poor, to which he (Jesus) gave him a sizeable amount of cooking fat. Jesus gave the instruction to boil it in a pot for 24 hours with the promise that a herd of pigs would arise from the pot - to be then slain, although not explicitly stated. St. Colmcille done as he was told and left it to boil, but a young maid at the time spotted said pot and stole a scoop of fat out to eat before continuing on with her day.
As a result, following Colmcille eagerly awaited for the pigs to come out, nothing happened. So he opened the lid to find a herd of mice. Due to their origins being in thievery, they were all cursed with only being able to get by as a species by doing so. Interesting story, although not corresponding with other folklore and historical origins.