You will be given a trivia clue, and the category it belongs to. You should answer with the best answer that belongs in the category and is described by the clue. For simplicity, answers should be in all lower cased letters.
Example: Category: HOMOPHONIC PAIRS 
Clue: It's a notation on a percussion store to clash
Example solution: cymbal symbol
Example explanation: "Cymbal" and "symbol" both have the same pronunciations but different meanings, hence they are homophonic pairs. A symbol is the notation and a cymbal is a percussion instrument that clashes and rings.

Problem: Category: FILL IN THE _____ 
Clue: Something hard to find resembles "a needle in a _____"

Solution: haystack