We never say we eat betel (tāmbūla), unlike other eatables. It is usually said that one ‘wears’ tāmbūla. It is not merely a food item but also is accompanied by areca nut, cardamom, and other aromatic ingredients that is worn (consumed) after food. The process is known as tāmbūla dharanam (wearing instead of eating) because it is not consumed fully. After chewing for some time, it is spitted out. Not only that it gives a red colour to the lips and tongue and is considered as an ornament hence the usage. There is a story behind this.
There was a demon named Tharaka. He got a boon that nobody else but only the son of Lord Shiva & Goddess Parvati could kill him. He became highly egoistic and disturbed all the worlds. Lord Muruga (Kartikeya) was born to Lord Shiva & Mother. There was a huge war fought against Tharaka under the leadership of Lord Muruga. Tharaka was killed at the end of the war. After the war, Lord Muruga and other Gods namely Indra, Upendra, Vishakendra etc were returning after the war. Before leaving Lord Muruga had the blessing of His Father and Mother. Devi had given a special weapon named ‘Vel’ with which Muruga could slay Tharaka.
After returning victoriously from the war, Muruga went to the Mother. They all were still in their war suits bathed in blood. They were eager to convey the news of victory to the Mother. Muruga, Indra and other Gods reached Mother’s abode and couldn’t even wait to take rest or remove their war suits. It was the time Devi had finished the feast and having tāmbūla. Om karpūra vīṭikāmoda samākarṣi digantarāyai namaḥ (who is enjoying a camphor laden betel roll, the fragrance of which is attracting people from all directions.); it is during that time the Gods and Muruga approached the Mother.
Lord Shiva was also waiting for them in Kailas to hear about the feat of Muruga and the war. Indra and others were thinking that the Lord will also give the sacred prasad. He usually gives it to Chandikeshwara first and then the remaining is given to rest of us. Even though the Lord was waiting for them, they went to the Mother first. We know that kids want to convey their feats first to Mothers. Father is more strict and might scold us.
There are certain rules to be followed to go to the Lord. One has to take a bath, wear sacred ash, new clothes, wear rudraksha, chant the 5 syllables and so on. One would not know if the Lord will get angry otherwise. But to go to Mother, no such rules are needed. Her ways are simple. Even if they were wearing blood-drenched clothes, all of them, straight away went to Devi.
After hearing all the feats of the war and the slaying of Tharaka, it is said in the scriptures that Mother gave the special tāmbūla named karpūra vīṭikā to all of them as prasad. Legends say that it is after taking the tāmbūla from the Mother, Kalidasa and others became great poets. The divine power of words can be attained by part taking Devi’s tāmbūla. Thus all of the Gods became happy and left Devi’s abode with the blessings and prasad in the form of karpūra vīṭikā.