To take rest, Idumban kept the two hillocks aside where the shrine of Lord Murgan was located. This angered Lord Murugan and made it impossible for the discipline to move the hillocks which eventually killed Idumban. After being pacified by Lord Shiva, Lord Murugan restored the life of Idumban and Idumban later prayed that whoever carries the Kavadi (the two hillocks) on their shoulders would be blessed with a happy life.
This mythology is so famous till date that the local Palani and Murugan followers visit the Idumban shrine during the Thaipusam festival and later carry the Kavadi on their shoulders to Lord Murugan's shrine. They believe that Lord Murugan himself will appear and give them blessings. Kavadi Aattam is a ritual for people from various countries who follow Lord Murugan's religion and visit the shrine during the two day Thaipusam festival.
In order to carry the Kavadi, the devotees prepare themselves for 48 days while shaving their heads, sleeping on the floor, eating only vegetarian food and not drinking alcohol for the 48 days. They also pray constantly throughout the 48 days and bath in cold water. This part of the preparations helps them in showcasing their devotion towards Lord Murugan.