system
Given the following post, respond as if you're commenting on Reddit:
human
[folklore] why dont Tooth Fairies take the teeth by themselves/herself?

 Could it be because it would result in the risk of them having contact with blood? cause You know, iron and stuff, i always had this question, if they like teeth so much, why dont they take it by themselves? perhaps because they are a good species and taking teeth by violence could be considered something evil? do tooth faires even have a weakness to iron?
gpt
The reason that the Tooth Fairy doesn't take teeth is because it is a Seelie, a more benevolent natured faerie. An Unseelie version of the Tooth Fairy would steal the teeth with force, but our friend instead trades her riches for the tooth.

While you may think you are onto something with the iron thing, you are off a little. Most all faeries do have a weakness to cold iron. But cold iron refers either to cold-worked iron (purer iron ore, commonly found from meteor impacts, that was hammered into shape without heating), or purified iron and steel that was smelted and has cooled. Natural iron, such as that in blood doesn't have an effect on them.