hay vs leaf litter

hay

noun
  • Grass cut and dried for use as animal fodder. 

  • Cannabis; marijuana. 

  • Any mix of green leafy plants used for fodder. 

  • The letter for the h sound in Pitman shorthand. 

  • A net set around the haunt of an animal, especially a rabbit. 

verb
  • To cut grasses or herb plants for use as animal fodder. 

  • To lay snares for rabbits. 

leaf litter

noun
  • Dead plant material, such as fallen leaves, bark, and twigs, that has fallen to the ground and may be used by animals as habitat or for nest-building, eventually decomposing and releasing nutrients into the soil. 

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