bird's nest vs cubbyhole

bird's nest

noun
  • Any tangle of fibers resembling a typical nest of a bird. 

  • A structure built by a bird as a place to incubate eggs and rear young. 

  • Any of several plants having some resemblance to the typical nest of a bird, eg, wild carrot (Dauca carota) 

cubbyhole

noun
  • A small compartment; a pigeonhole 

  • A glove compartment 

  • A small, snug room which may be used as a place of privacy and safety by children 

verb
  • To restrict, limit or narrowly define; to pigeonhole. 

How often have the words bird's nest and cubbyhole occurred in a corpus of books? (source: Google Ngram Viewer )