Like other parts of India, people in Bihar celebrate this festival to make the Snake God happy. On this occasion they worship snakes so that these reptiles do not harm them. Nag Panchami is a festival of snake. People celebrate Nag Panchami Festival on the fifth day of the brilliant fortnight in the month of Shravan.
Many pilgrims as well as tourists from all over the country visit temples specially devoted to snakes and worship them on the day of Nag Panchami Festival. The temples dedicated to Lord Shiva are also preferential places for reverence as snakes are considered very close and dear to Shiva.
The Nag Panchami festival is celebrated to appease snakes which have been a dangerous reptile and bite people. Its rationality could be understood from the fact that snake biting is quite normal in India and people are scared of snakes. People offer milk during Nag Panchami to snake god. The prime centre of naga worship is Rajgir. Mahabharata describes Rajgir as the abode of serpents and excavations have revealed numerous objects used in serpent cult. In fact, naga worship is wide spread through out India.