ferret vs mousekin

ferret

noun
  • An often domesticated mammal (Mustela putorius furo) rather like a weasel, descended from the polecat and often trained to hunt burrowing animals. 

  • A diligent searcher. 

  • The black-footed ferret, Mustela nigripes. 

verb
  • To uncover and bring to light by searching; usually to ferret out. 

  • To hunt game with ferrets. 

mousekin

noun
  • A little mouse. 

  • A baby mouse. 

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