The little boy was found walking down the side of a road in the town wearing just some underpants and a t-shirt by a motorist who took him to a police station on Saturday night, newspaper La Depeche reports.
The mother turned up drunk at the station in the early hours of the morning to report her son missing. Police arrested her immediately.
It was only when the father returned home a few hours later that it was discovered their one-year-old son had been left home alone too.
A spokesperson for the local police said: “The couple had argued, and the man left, leaving the mother alone with the two children. The mother decided to go party anyway.
“We still don’t know how the boy managed to open the door to get out.”