habitat vs milieu

habitat

noun
  • A place in which a person lives. 

  • Conditions suitable for an organism or population of organisms to live. 

  • A terrestrial or aquatic area distinguished by geographic, abiotic and biotic features, whether entirely natural or semi-natural. 

  • A place or type of site where an organism or population naturally occurs. 

milieu

noun
  • A social environment or setting. 

  • A group of people with a common point of view; a social class or group. 

  • An environment or setting; a medium. 

How often have the words habitat and milieu occurred in a corpus of books? (source: Google Ngram Viewer )