The snake bit 9-year old Hakim Nollah and his sister Mumtaz Khatun in sleep at Banamalipur village in the early hours today.
Initially their parents thought that they were bitten by ants but once they complained of stomach ache and started vomitting, they were rushed to Diamond Harbour Hospital.
While the boy was declared 'brought dead' at the hospital, the girl died this morning, hospital authorities said.