That is if the nagas grew to become way too populous and started to torment the individuals. This is when they were cursed by their grandfather, Lord Brahma, with annihilation. The nagas begged for mercy but were sent to Patala, the underworld. These are claimed to inhabit the bottom https://waylonymalx.yomoblog.com/42777519/the-smart-trick-of-23naga-that-no-one-is-discussing