article_snippet.sent: fiercely territorial song also serves as a warning for rivals to stay away.
article_snippet.sent: The experts analysed the frequencies of different songs.  
article_snippet.sent: The females, meanwhile, seem to like some of the songs more than others.
article_snippet.sent: This revealed that people sang one song when people could simply smell a female and another one when people could see she.
article_snippet.sent: When people could merely smell a potential mate, people belted out an extremely shrill and complex song, perhaps in an attempt to make people known.
highlights_snippet.sent: Attracts mates by singing various songs, which also warn off rivals .
  