Encyclopedia Entry:
A type of Harpy with a beautiful singing voice that absolutely loves singing. Her songs are infused with a lot of magical energy, and men who hear them become entranced by it and end up moving in the direction that they hear the song coming from. Most sirens live near the ocean, and due to this many ships have disappeared mid-voyage, never-to-return, after the men aboard were lured by their songs. Thus sailors are very fearful of them.
They choose their prey from among the men who were drawn to them by their songs, but in this case, they aren’t the only threats. Most of the time, all kinds of monsters who are after the men are lurking nearby. Once the songs have ended, the men who were entranced by the songs will be attacked all at once, and will probably end up being taken away.
Normally, all they do is sing all the time, but when they come into heat, they sing even more frequently. There’s no doubt about it, because more and more ships disappear mid-voyage during these periods than at other times. Sirens with husbands keep singing “the special song” to their husbands, to their husbands so their sex lives stay healthy and active.