Here's an interesting verse near said mention (spoken by the Lord's brother many say)...
Jude 1:6
And the angels which kept not their first estate, but left their own habitation, he hath reserved in everlasting chains under darkness unto the judgment of the great day.
There’s contention by some that the Nephilium/fallen angels drowned in Noah’s time became disembodied and thereby demons.
That the Nephilium/fallen angels running around loose in our era were not caught in the flood somehow.
What do I know. Plausible.