There is something similar between these two fragrances. I don't know what it's called, but it smells kind of herbal. It's very obvious in L'Oiseau de Nuit, one of the main components, and slightly less obvious in Ambre Sultan but still very much present. Can anyone help me identify this note? (I don't like it, and I want to avoid it in the future. More's the pity, because otherwise L'Oiseau de Nuit is fantastic.)