gnat vs harvestman

gnat

noun
  • Any small insect of the order Diptera, specifically within the suborder Nematocera. 

  • An annoying person. 

harvestman

noun
  • An order of terrestrial, non-venomous arachnids with often very long legs: Opiliones. 

  • A field-worker who works to gather in the harvest. 

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