Compulsive or uncontrollable urge.

A mania for finding fault or an uncontrollable urge to nitpick (trivial, unnecessary, detailed, and often unjustified faultfinding).

This phrase is from cacoëthes carpendi which is derived from kakoethes, a Greek word that combines kakos, "bad", with ethos, "habit"; and which describes any compulsion or uncontrollable urge.

Cacoëthes can be used alone to mean "mania" or "passion", even "disease". With carpendi, a form of carpere, meaning "to pluck", as fruit from a tree, the phrase becomes highly useful in describing the uncontrollable urge to be a nitpicker.

1. A strong passion to criticize or a mania for finding fault with others: The project's supervisor allowed his cacoëthes carpendi to get out of control and really offended people on the job site.
2. Etymology: derived from kakoethes, a Greek word that combines kakos, "bad" with ethos, "habit" and describes "any compulsion" or "uncontrollable urge".