cockroach vs vermin

cockroach

noun
  • A person or a member of a group of people regarded as undesirable and rapidly procreating. 

  • A Tutsi. 

  • A person from New South Wales. 

  • A black or brown straight-winged insect of the order Blattodea. 

vermin

noun
  • Obnoxious, or mean and offensive person or people. 

  • Any one of various common types of small insects or animals which cause harm and annoyance. 

  • Animals that prey on game, such as foxes or weasels. 

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