On the fifth day of the bright half of Shravana month of Hindu calendar, people worship the snake or /nag/. The day is known as /Nag Panchami/. Nag Panchami has a special significance and is celebrated by the devotees with lot of faith, fear and devotion. It is firmly believed that the serpent lord associated with Lord Subrmanya who will be pleased by this worship will mitigate their sufferings and bring happiness. On this day, people visit temples specially dedicated to snakes and worship them.
In South India, the serpent is given a pride of place and you will find Naga idols installed in almost all temples and even on roadside platforms. It is believed that any harm done to snakes create miseries and sufferings. Serpent worship is very widely followed. The major Hindu gods, Lord Shiva has serpent as an ornament round his neck and Lord Vishnu has serpent Adhisesha as his bed and he is called Seshashayana (person sleeping on snake)
The day preceding Nag Panchami i.e. the fourth day of the bright half of Shravan month is called 'Naga Chauthi'. On this day women take head bath and wearing wet clothes which marks sanctity and divinity, visit the snake banas in the morning. Raw milk and ghee are offered followed by /haladi/ (turmeric powder), /kumkum, chandan/ (sandalwood paste), rice and flowers. Prayers are offered for the well being of the families. Those who offer such worship on this day normally undertake fasting on the day.
On Nag Panchami, people also make images of snakes using cow dung and place them on either side of the entrance to the house to welcome the snake god. In some families it is also a tradition to keep a silver idol of Serpent in the pooja room and worship by pouring raw milk and ghee, and decorate the idol with haladi, kumkum and flowers. Some people have the tradition of making an idol of serpent by mixing 'chandan' (sandal wood paste), 'haladi' (turmeric powder), and 'kumkum'' (sindhoor), and 'kesari' (saffron) and placed on a metal plate and worshiped. In some families, figures of snakes are drawn with red sandalwood paste on wooden boards, or purchase clay images of snakes coloured yellow or black. These are then worshiped and offered milk, ghee and flowers.
Nag Panchami is also connected with the following legend of Lord Krishna. Young Krishna was playing ball with the other cowboy friends, when suddenly the ball got entangled in the high branch of a tree. Krishna volunteered to climb the tree and fetch the ball. But below the tree the river Yamuna was flowing in full glory, in which the terrible poisonous snake Kalinga was living. Nobody dared to go near that place. Lord Krishna ignoring the warnings of his friends jumps into the water. The dangerous "Kalinga" serpent comes up. But Krishna was ready and jumping on the snake’s head, starts dancing on its head. Kalinga realizes the strength of Lord Krishna and pleads with Krishna: "Please, do not kill me." Krishna takes sympathy on Kalinga and after taking a promise that henceforth he would not harm anybody, he let the snake go free into the river again. Hence, Nag Panchami is also commemorated as a day of victory of Lord Krishna over Kalinga the legendary snake.
It is widely believed that snakes like milk. As this is the day of the serpents, devotees pour raw milk into snake banas around the house or near the temples to propitiate them. Sometimes, a small pot of milk with some flowers is placed near the holes of snake banas so that the snakes may drink it. It is firmly believed that if a snake actually drinks the milk, it is considered to be extremely auspicious and the devotees are blessed.
Temples devoted to Lord Subramanya (Lord Muruga-Kartikeya) conduct special poojas and prayers on this day and large number of devotees visits such temples to offer prayers.
A unique feature in South India is that Nag Panchami is also celebrated as Brother-Sisters Day. On this occasion, brothers visit the houses of their married sisters. Sisters apply milk and ghee on the back of the body of their brothers by using a flower followed by turmeric powder and kumkum. Food and eatables are offered and gifts are given with prayers to serpent Lord to bless their brothers with health, wealth and happiness. This has a very unique social significance which binds the two families.
The difference between Nag Panchami and other Hindu festivals like Holi, Diwali, and Navaratri is that Nag Panchami is not associated with pomp and splendor associated with other festivals but celebrated with lots of faith, sanctity and devotion.